// ============================================================
// FILE: theory/pathology/part1-pathology/flash-pyq.js
// SUBJECT: Pathology | CHAPTER: complete | DECK: Flash PYQ
// ============================================================

var CARDS_Microbiology_CNSMicrobiology_FlashPYQ = [
  {
    "q": "25 years male RTA victim presented with rapid pulse, cold clammy cyanotic skin, tachypnea and landed in emergency ward in unconscious state. What is the diagnosis? Classify the disease, write in detail about the pathogenesis, morphology and evolution of the disease.",
    "a": "Dx: Hypovolemic/Hemorrhagic Shock. Classification: Hypovolemic, Cardiogenic, Distributive (Septic/Anaphylactic/Neurogenic), Obstructive. Pathogenesis: Decreased CO → SNS activation → vasoconstriction → neurohumoral compensation → decompensation → irreversible shock. Stages: Compensated, Progressive, Irreversible. Morphology: Brain (ischemic injury), Kidney (ATN - pale cortex, congested medulla), Heart (subendocardial necrosis), Lung (ARDS/shock lung), GI (hemorrhagic necrosis), Adrenal (cortical lipid depletion)."
  },
  {
    "q": "50/male vegetarian, presented with pallor, paresthesia of extremities. O/E he had beefy tongue. What is your diagnosis? How will you investigate this patient further and establish the diagnosis? Classify RBC disorders according to etiology.",
    "a": "Dx: Pernicious Anemia / Vit B12 deficiency (Megaloblastic anemia). Investigations: CBC (macrocytic anemia, hypersegmented neutrophils), Peripheral smear (macro-ovalocytes), Serum B12 levels, Serum LDH & bilirubin (elevated), Schilling test, Anti-intrinsic factor & anti-parietal cell antibodies, Bone marrow (megaloblasts). RBC disorder classification by etiology: Blood loss (acute/chronic), Decreased production (aplastic, nutritional, marrow infiltration), Increased destruction (hemolytic - intrinsic/extrinsic)."
  },
  {
    "q": "18 years male your friend was diagnosed as Hodgkin's lymphoma. How will you empathise with him and his family members & support them?",
    "a": "SPIKES protocol: Setting (private, comfortable), Perception (what they know), Invitation (how much they want to know), Knowledge (break news gently), Empathy (acknowledge emotions, non-verbal cues), Summary. Support: Reassure treatability of HL, discuss treatment options (ABVD chemo, radiation), address fears, involve family, refer counselling/support groups, follow-up plan."
  },
  {
    "q": "Write short notes on Calcification.",
    "a": "Types: Dystrophic (dead/damaged tissue, normal calcium metabolism - TB, atherosclerosis, old infarcts) vs Metastatic (normal tissue, hypercalcemia - hyperparathyroidism, vit D toxicity, affects kidney/lung/gastric mucosa). Mechanism: Dystrophic - membrane damage → calcium influx, phospholipid degradation, alkaline phosphatase activity. Metastatic - excess calcium × phosphate product. Morphology: chalky white deposits, von Kossa stain (black). Pathologic significance: vessel stiffening, organ dysfunction."
  },
  {
    "q": "10 years female was administered an analgesic injection IM and immediately collapsed. What is the type of reaction? What is the pathogenesis of this reaction?",
    "a": "Dx: Anaphylaxis - Type I Hypersensitivity (IgE mediated). Pathogenesis: Sensitization phase - antigen → IgE production → mast cell/basophil binding. Elicitation phase - re-exposure → antigen crosslinks IgE → mast cell degranulation → Primary mediators: histamine, heparin, tryptase; Secondary mediators: prostaglandins, leukotrienes (LTC4, LTD4), PAF. Effects: vasodilation, increased permeability, bronchospasm, laryngeal edema. Management trigger: Epinephrine, antihistamines, steroids."
  },
  {
    "q": "10 years male presented with evening raise of temperature, neck nodes. His father was treated for cough with expectoration for 6 months. What is your diagnosis? Write about pathogenesis and morphology of this illness.",
    "a": "Dx: Primary Pulmonary Tuberculosis (Mycobacterium tuberculosis). Pathogenesis: Inhalation → alveolar macrophage phagocytosis → Ghon focus (subpleural) → lymphatic spread to hilar nodes → Ghon complex → delayed hypersensitivity (Type IV) → granuloma formation. Morphology: Ghon focus - caseating granuloma (epithelioid cells, Langhans giant cells, lymphocytes, central caseous necrosis). Ghon complex = Ghon focus + draining lymph nodes + lymphangitis. Fate: Healing (calcification), Progressive primary TB, Miliary TB, Post-primary reactivation."
  },
  {
    "q": "30 years male presented with fever with rigors. He had H/o dark coloured urine after admission and also had cloudy consciousness. What is the diagnosis? What is the role of peripheral smear in diagnosis?",
    "a": "Dx: Malaria (Plasmodium falciparum - Cerebral malaria + Blackwater fever). Peripheral smear role: Species ID (P. falciparum - ring forms, banana-shaped gametocytes, multiple rings/RBC, no enlarged RBCs; P. vivax - enlarged RBCs, Schüffner's dots, all stages; P. malariae - band forms; P. ovale - oval RBCs, fimbriated). Quantify parasitemia (% RBCs infected). Thick smear - detection; Thin smear - speciation. Dark urine = hemoglobinuria from intravascular hemolysis."
  },
  {
    "q": "Write about the pathogenesis of obesity.",
    "a": "Pathogenesis: Energy imbalance (intake > expenditure). Key mediators: Leptin (adipokine - satiety signal; leptin resistance in obesity), Adiponectin (decreased - insulin resistance), Ghrelin (hunger hormone - increased). Genetic factors: FTO gene, MC4R mutations, monogenic obesity. Hypothalamic dysregulation: Arcuate nucleus - NPY/AgRP (orexigenic) vs POMC/CART (anorexigenic). Neuroendocrine: hypothyroidism, Cushing's. Gut microbiome. Complications: Type 2 DM, dyslipidemia, HTN, NASH, OSA, CVD, certain cancers."
  },
  {
    "q": "60 years male presented with low back ache. He had multiple lytic lesions of bones on skeletal survey. Serum electrophoresis and bone marrow was done to establish diagnosis. What is your diagnosis? What are the findings in bone marrow and electrophoresis?",
    "a": "Dx: Multiple Myeloma. Bone marrow: >10% plasma cells (sheets/clusters), abnormal plasma cells (Russell bodies, Dutcher bodies, flame cells, Mott cells), Bence Jones casts. Electrophoresis: M-spike (monoclonal peak) in gamma region (IgG most common, then IgA), decreased normal immunoglobulins. Urine: Bence Jones protein (free light chains). Other: Rouleaux formation on smear, hypercalcemia, renal failure (myeloma kidney), CRAB criteria (Calcium, Renal, Anemia, Bone lesions)."
  },
  {
    "q": "Classify transfusion reactions. How will you investigate a case of transfusion reactions?",
    "a": "Classification: Immunologic - Acute hemolytic (ABO incompatibility), Delayed hemolytic, Febrile non-hemolytic (anti-leukocyte antibodies), Allergic/Anaphylactic, TRALI, Graft vs Host. Non-immunologic - Circulatory overload (TACO), Septic (bacterial contamination), Hypothermia, Citrate toxicity. Investigations: Stop transfusion, send blood bag + patient sample. Direct Coombs test, Repeat ABO/Rh typing, Urine for hemoglobin, Serum bilirubin, LDH, Haptoglobin, Blood culture (bag & patient), CBC, Coagulation profile (if DIC suspected)."
  },
  {
    "q": "40 years male with splenomegaly on investigations had total count of 1,20,000 cells/mm3 and peripheral smear showed predominance of myeloid precursors. What is your diagnosis? Draw diagram of peripheral smear. What is the common genetic event in this condition?",
    "a": "Dx: Chronic Myeloid Leukemia (CML). Peripheral smear: Leukocytosis with full myeloid spectrum (myeloblasts, promyelocytes, myelocytes, metamyelocytes, bands, neutrophils), basophilia, eosinophilia, thrombocytosis, low LAP score. Genetic event: Philadelphia chromosome - t(9;22)(q34;q11) → BCR-ABL1 fusion gene → constitutively active tyrosine kinase → uncontrolled proliferation. Phases: Chronic → Accelerated → Blast crisis. Treatment target: Imatinib (TKI)."
  },
  {
    "q": "Describe normal hemostasis and coagulation cascade.",
    "a": "Hemostasis: Primary (platelet plug) - vascular injury → vasoconstriction → platelet adhesion (vWF-GpIb) → activation (ADP, TXA2) → aggregation (fibrinogen-GpIIb/IIIa). Secondary (coagulation) - Extrinsic (TF+VII→X), Intrinsic (XII→XI→IX→X), Common (X+V→Prothrombin→Thrombin→Fibrinogen→Fibrin). Final: cross-linked fibrin clot by Factor XIII. Regulatory: Antithrombin III, Protein C&S, TFPI, tPA (fibrinolysis). Platelet factors: PF3 (phospholipid surface), PF4 (heparin neutralizer)."
  },
  {
    "q": "30 years female immediately after delivery went into sudden circulatory failure. She had profuse bleeding per vaginum and from venepuncture sites. What is your diagnosis? What is the Pathophysiology? How will you investigate this patient?",
    "a": "Dx: DIC (Disseminated Intravascular Coagulation) - triggered by amniotic fluid embolism / abruptio placentae / PPH. Pathophysiology: Obstetric trigger → massive TF release → systemic thrombin activation → microthrombi (organ failure) + consumption of clotting factors/platelets → paradoxical bleeding. Investigations: CBC (thrombocytopenia), PT/APTT (prolonged), Fibrinogen (decreased <150 mg/dL), D-dimer (elevated), FDP (elevated), Peripheral smear (schistocytes/microangiopathic hemolysis), Blood culture."
  },
  {
    "q": "1 year male child was brought with loss of vision and mass lesion of the eyeball. There was a family H/o sarcoma of the long bone in the sibling. What is your diagnosis? What is the molecular mechanism involved in this family? Describe the normal cell cycle and how this gene affects cell cycle. Name 3 other genes involved in familial syndromes.",
    "a": "Dx: Retinoblastoma (familial/bilateral). Molecular mechanism: Knudson's 'Two-hit hypothesis' - RB1 gene (chromosome 13q14), tumor suppressor. First hit - germline mutation (inherited), Second hit - somatic mutation → loss of heterozygosity → loss of Rb protein → uncontrolled E2F transcription factor activity → unregulated cell cycle entry (G1→S). Cell cycle: Rb normally inhibits E2F in G1; CDK4/6-cyclin D phosphorylates Rb → releases E2F. Other familial tumor genes: TP53 (Li-Fraumeni), BRCA1/2 (breast/ovarian), APC (FAP/colorectal), NF1/NF2, VHL, MEN1/RET."
  },
  {
    "q": "7 years male child is found lying down on the road with convulsions with his mother. How will you react as a medical student and help them?",
    "a": "First aid/ethical response: Ensure safety of scene, Call for help (108/emergency), Position patient - lateral decubitus (recovery position), Airway - clear, time the seizure, Do not restrain, Do not put objects in mouth, Loosen tight clothing, Stay with patient, Inform ambulance of situation. Medical student ethics: Act within competence, Good Samaritan principle, Do no harm, Refer appropriately after stabilization, Document if possible, Inform parents/guardian."
  },
  {
    "q": "50 years male who was a diabetic has developed an ulcer in the foot of size 6 x 4 cm. His last toe was covered with necrotic slough. What is your diagnosis? What is the pathogenesis and pathology involved in this complication?",
    "a": "Dx: Diabetic foot - Wet gangrene / Diabetic neuropathic ulcer. Pathogenesis: Microangiopathy (PAS+ basement membrane thickening) → ischemia. Neuropathy (sensory → painless trauma, motor → foot deformity, autonomic → dry skin). Immunopathy → impaired neutrophil function → superimposed infection. Pathology: Necrosis (coagulative initially), bacterial invasion → liquefactive → wet gangrene. Atherosclerosis (large vessel) + arteriolar hyalinosis (small vessel). Slough = dead tissue + bacteria + exudate."
  },
  {
    "q": "8 years female child was hailing from a poor family and was found to have loss of muscle mass and subcutaneous fat, she was emaciated. What is your diagnosis? How will you categorize nutritional disorders?",
    "a": "Dx: Marasmus (Protein-Energy Malnutrition). Features: severe wasting, loss of muscle & fat, preserved intellect, 'old man face', no edema, hair changes less prominent. Classification of nutritional disorders: PEM (Marasmus, Kwashiorkor, Marasmic-Kwashiorkor), Vitamin deficiencies (fat soluble: A,D,E,K; water soluble: B1,B2,B3,B6,B12,C,Folate), Mineral deficiencies (Iron, Zinc, Iodine), Obesity/Overnutrition. WHO grades of malnutrition: Grade I-IV by weight-for-age."
  },
  {
    "q": "Write about the pathogenesis of amyloidosis.",
    "a": "Pathogenesis: Misfolded proteins resist degradation → extracellular deposition in beta-pleated sheet configuration. Types: AL (light chain - plasma cell dyscrasias), AA (SAA protein - chronic inflammation), ATTR (transthyretin - senile/familial), Aβ (Alzheimer's), β2-microglobulin (dialysis). Mechanism: Overproduction → abnormal folding → aggregation → oligomers (toxic) → fibrils → Congo red positive, apple-green birefringence under polarized light, P-component, RAGE receptor interaction → organ dysfunction. Organs: kidney (proteinuria), liver, spleen (sago/lardaceous), heart (restrictive CMP)."
  },
  {
    "q": "25 years male had a cut injury in his hand and wound was sutured immediately. How does healing take place in such wound? What are the factors delaying wound healing?",
    "a": "Healing by Primary Intention (1° union): Day 1-3 - Hemostasis, inflammation (PMNs), clot fills wound. Day 3-5 - Macrophages, granulation tissue, angiogenesis, fibroblast migration, collagen type III. Day 5-14 - Re-epithelialization, collagen crosslinking, scar maturation (type III→type I). Week 3+ - Wound strength increases (max ~70-80%). Factors delaying healing: Infection, Diabetes, Malnutrition (Vit C, Zinc, protein deficiency), Poor blood supply, Steroids, Foreign body, Wound tension, Irradiation, Old age, Uremia, Malignancy."
  },
  {
    "q": "What are the subtypes of Hodgkin Lymphoma? Also write about types of RS cells.",
    "a": "WHO subtypes: Classical HL (95%) - Nodular Sclerosis (most common, young females, mediastinal), Mixed Cellularity (EBV-related, older males), Lymphocyte-Rich (best prognosis), Lymphocyte-Depleted (worst prognosis, HIV-related); Nodular Lymphocyte Predominant HL (5%) - LP cells ('popcorn cells'). Reed-Sternberg cells: Classic RS - binucleated/bilobed, 'owl eye' nucleoli (CD15+, CD30+); Lacunar cells (NS subtype); Mononuclear variant; Lymphocytic & Histiocytic (L&H/popcorn cells - NLPHL, CD20+, CD45+, EMA+); Pleomorphic (LD subtype)."
  },
  {
    "q": "20 years male following antibiotic intake had total leukocyte count of 1200 cells/mm3 and absolute neutrophil count of 120 cells. What is your diagnosis? What is the pathogenesis of this condition?",
    "a": "Dx: Drug-induced Agranulocytosis / Severe Neutropenia (ANC <500 = severe agranulocytosis). Pathogenesis: Immune-mediated (hapten mechanism - drug binds protein → antibody formation → neutrophil destruction; direct antibody against neutrophil antigens; immune complex deposition); Toxic direct suppression of myelopoiesis (chloramphenicol, cytotoxics). Causative: beta-lactams, sulfonamides, carbimazole, clozapine, NSAIDs. Risk: life-threatening infections. Morphology: Hypocellular marrow, absent myeloid precursors, monocytosis, lymphocytosis."
  },
  {
    "q": "Write about infections transmitted by blood transfusion. How will you prevent it?",
    "a": "Infections: Viral - HIV (window period 11-22 days), HBV (window 38-50 days), HCV (window 66-82 days), CMV, EBV, HTLV-I/II, Parvovirus B19, West Nile virus. Bacterial - Yersinia enterocolitica (RBCs), Staphylococcus (platelets). Parasitic - Malaria, Chagas disease (Trypanosoma cruzi), Babesia. Prevention: Donor screening (questionnaire - HIV risk behavior, travel), Mandatory testing (ELISA for HIV, HBsAg, anti-HCV, VDRL, malaria antigen), NAT (Nucleic Acid Testing) to reduce window period, Leukodepletion (CMV prevention), Pathogen inactivation (FFP, platelets), Single-donor preference."
  },
  {
    "q": "20 years female had hematocrit of 20%, reticulocytosis, hyperbilirubinemia, peripheral smear revealed anisopoikilocytosis and target cells. What is the pathophysiology of this disease?",
    "a": "Dx: Thalassemia (likely Beta-thalassemia major / HbE-beta thalassemia). Pathophysiology: Defective globin chain synthesis → imbalanced alpha:beta ratio → excess unpaired chains → precipitate → inclusions → membrane damage → ineffective erythropoiesis (intramedullary hemolysis) + peripheral hemolysis → anemia → compensatory erythropoiesis (hepatosplenomegaly, skeletal changes - crew-cut skull) → high output heart failure. Target cells: excess membrane relative to Hb. Unconjugated hyperbilirubinemia from hemolysis. Reticulocytosis = compensatory marrow response."
  },
  {
    "q": "WHO classification of Acute Myeloid Leukemia.",
    "a": "WHO 2016 Classification AML: 1) AML with recurrent genetic abnormalities: t(8;21) AML-ETO, inv(16)/t(16;16) CBFβ-MYH11, t(15;17) PML-RARα (APL/M3), t(9;11) MLL-MLLT3, t(6;9), inv(3), t(1;22), NPM1 mutation, biallelic CEBPA mutation. 2) AML with myelodysplasia-related changes. 3) Therapy-related AML (alkylating agents, topoisomerase inhibitors). 4) AML, NOS (FAB subtypes M0-M7): M0 undifferentiated, M1 minimal maturation, M2 maturation, M3 promyelocytic, M4 myelomonocytic, M5 monocytic, M6 erythroid, M7 megakaryoblastic. Diagnosis: ≥20% blasts in BM."
  },
  {
    "q": "35 years old male presented with rapid pulse, cold clammy skin, tachypnoea with hypotension. History of fever for more than 1 week with increased total WBC count. What is your diagnosis? Write in detail about the pathogenesis, morphology and how will you evaluate this condition?",
    "a": "Dx: Septic Shock (distributive shock - gram-negative bacteremia likely). Pathogenesis: LPS (gram-neg) / Lipoteichoic acid (gram-pos) → TLR4 activation → macrophage/monocyte activation → cytokine storm (TNF, IL-1, IL-6, IL-12) → endothelial activation/injury → NO (vasodilation) → decreased SVR → SIRS → MODS. DIC component via TF expression. Morphology: Adrenal hemorrhage (Waterhouse-Friderichsen), ATN (kidney), ARDS (lung - DAD), Centrilobular necrosis (liver). Evaluation: Blood culture (×2), CBC, CRP, Procalcitonin, Lactate, LFT/RFT, ABG, Coagulation profile, Cultures (urine, sputum), Echo, qSOFA/SOFA score."
  },
  {
    "q": "8 years old girl presented with malaise and fatigue. On examination yellowish sclera with hepatosplenomegaly noted. Family history revealed similar complaints in her sibling also. Her Haemoglobin level is 7.8 g/dl. X-Ray skull showed 'crew-cut' appearance. What is your diagnosis? Write in detail about etiopathogenesis, morphology and laboratory investigations needed to confirm the diagnosis.",
    "a": "Dx: Beta-Thalassemia Major (Cooley's anemia). Etiopathogenesis: Autosomal recessive, mutations in beta-globin gene (Chr 11) → absent/reduced beta chains → excess alpha chains → precipitation → RBC membrane damage → ineffective erythropoiesis + hemolysis → severe anemia → compensatory extramedullary hematopoiesis (hepatosplenomegaly, skull expansion → crew-cut). Morphology: Marrow expansion, erythroid hyperplasia, hemosiderosis (transfusion-related), Gamna-Gandy bodies (spleen). Lab: CBC (severe microcytic hypochromic anemia), Peripheral smear (target cells, teardrops, nucleated RBCs), Hb electrophoresis (HbF elevated, HbA absent/minimal, HbA2 variable), Serum iron (elevated), Serum ferritin (elevated), LDH (elevated), Indirect bilirubin (elevated), Genetic testing (mutation analysis)."
  },
  {
    "q": "Define necrosis and its types.",
    "a": "Necrosis: Pathological cell death with cell membrane disruption, enzyme leakage, inflammation. Types: 1) Coagulative - ischemia (except brain), preserved architecture, 'ghost cells', firm pale infarcts. 2) Liquefactive - brain infarct, abscesses; enzymatic digestion → liquid cyst. 3) Caseous - TB; soft crumbly cheese-like, granuloma + caseation; no architecture. 4) Fat - enzymatic (pancreatitis - lipase action, calcium soap = saponification) vs traumatic. 5) Gangrenous - dry (ischemia, coagulative), wet (bacterial superinfection, liquefactive) gangrene. 6) Fibrinoid - immune complexes in vessel walls, SLE, malignant HTN."
  },
  {
    "q": "Write short notes on Vitamin D deficiency.",
    "a": "Vitamin D deficiency: Sources - sunlight (UVB → D3), diet (D2/D3). Metabolism: Skin → D3 → liver (25-OH) → kidney (1,25-(OH)2 D3 = calcitriol, active form). Functions: Calcium & phosphate absorption, bone mineralization, immune modulation. Deficiency effects: Children → Rickets (craniotabes, frontal bossing, rachitic rosary, pigeon chest, bow legs, Harrison's sulcus); Adults → Osteomalacia (bone pain, proximal myopathy, Looser zones on X-ray). Pathology: Excess osteoid (unmineralized), widened epiphyseal plate. Lab: Low 25-OH Vit D, low Ca, low PO4, elevated ALP, elevated PTH. Treatment: Vit D supplementation, calcium."
  },
  {
    "q": "Write about Type IV Hypersensitivity reaction.",
    "a": "Type IV = Delayed-type hypersensitivity (DTH) / Cell-mediated immunity (no antibody). Mechanism: Sensitization - APC presents antigen → CD4+ Th1 cell priming → memory T cells. Elicitation (48-72 hrs) - re-exposure → Th1 activation → IL-2 (T cell proliferation), IFN-γ (macrophage activation → granuloma), TNF (inflammation), IL-3+GM-CSF (monocyte recruitment). Subtypes: DTH (tuberculin-type, PPD skin test), Contact dermatitis (CD8+), Granulomatous (TB, sarcoid, leprosy, Crohn's). Examples: TB skin test (Mantoux), contact dermatitis (nickel, poison ivy), graft rejection, chronic granulomatous diseases. CD8 cytotoxicity: direct killing of target cells."
  },
  {
    "q": "Write short notes on Etiopathogenesis of ITP (Idiopathic Thrombocytopenic Purpura).",
    "a": "ITP = Immune Thrombocytopenic Purpura. Etiology: Primary (idiopathic); Secondary (SLE, HIV, HCV, H. pylori, drugs). Pathogenesis: Molecular mimicry or autoimmune dysregulation → autoantibodies (IgG) against platelet surface glycoproteins (GpIIb/IIIa, GpIb/IX) → opsonized platelets phagocytosed by splenic macrophages (Fc receptor-mediated) → thrombocytopenia. Also: T-cell mediated direct platelet/megakaryocyte destruction, impaired thrombopoiesis. Morphology: Spleen - mild enlargement, germinal center hyperplasia. Bone marrow - megakaryocyte hyperplasia (increased production attempt). Lab: Thrombocytopenia, large platelets (megathrombocytes), normal PT/APTT, positive anti-platelet antibodies, bone marrow (increased megakaryocytes)."
  },
  {
    "q": "Write short notes on Philadelphia chromosome.",
    "a": "Philadelphia chromosome: t(9;22)(q34;q11.2) translocation. Gene: BCR-ABL1 fusion (c-ABL from Chr 9 + BCR from Chr 22) → constitutively active tyrosine kinase → uncontrolled cell proliferation (RAS, JAK-STAT, PI3K-AKT pathways), anti-apoptosis, genomic instability. Found in: CML (95%), ALL (25-30% adult ALL, poor prognosis marker). CML phases: Chronic (indolent, TKI responsive) → Accelerated (>10% blasts, additional mutations) → Blast crisis (>20% blasts, AML/ALL-like). Diagnosis: Karyotype, FISH, RT-PCR (BCR-ABL1 transcript quantification). Treatment: Imatinib (1st gen TKI), Dasatinib, Nilotinib; Stem cell transplant in blast crisis."
  },
  {
    "q": "Describe the morphology of amyloidosis.",
    "a": "Gross: Congo red staining → salmon-pink. Polarized light → apple-green birefringence (pathognomonic). Spleen - Sago spleen (nodular deposits in follicles) or Lardaceous spleen (diffuse, waxy-gray). Kidney - enlarged, pale, waxy cortex; glomerular deposits → proteinuria → nephrotic syndrome. Liver - enlarged, pale, waxy; perisinusoidal deposits (space of Disse). Heart - gray-pink waxy deposits; restrictive CMP. Blood vessels - perivascular deposits. GI - submucosal deposits. Micro: Homogeneous eosinophilic extracellular material, stains with Congo red, PAS positive, Thioflavin T (fluorescence), Beta-pleated sheet on electron microscopy (EM shows non-branching fibrils 7.5-10 nm diameter)."
  },
  {
    "q": "Enumerate the various anti-coagulants utilized in clinical pathology lab for routine blood investigations. Write about their mechanism and their uses.",
    "a": "Anticoagulants: 1) EDTA (K2/K3 EDTA, purple top) - Mechanism: chelates Ca2+. Use: CBC, ESR, blood group, PBF, HbA1c; preferred for hematology. 2) Sodium Citrate (blue top) - Mechanism: chelates Ca2+ (reversible). Use: PT, APTT, coagulation studies; 9:1 ratio blood:citrate. 3) Heparin (green top) - Mechanism: activates antithrombin III → inhibits thrombin & Xa. Use: Emergency electrolytes, plasma chemistry, fragile chromosomal studies, RBC fragility test. 4) Sodium Fluoride/Potassium Oxalate (grey top) - Mechanism: F inhibits glycolysis (enolase inhibition), oxalate chelates Ca. Use: Blood glucose, lactate (preserves glucose up to 3 days). 5) Acid Citrate Dextrose (ACD) - blood banking, HLA typing, DNA studies."
  },
  {
    "q": "Write about opportunistic infections in AIDS.",
    "a": "OIs in AIDS (CD4 count threshold): Pneumocystis jirovecii pneumonia (PCP) - CD4 <200 (ground-glass opacity, bilateral); CMV retinitis/colitis - CD4 <50; Toxoplasma gondii - CD4 <100 (ring-enhancing brain lesions); Cryptococcus neoformans - CD4 <100 (meningitis, India ink); MAC (Mycobacterium avium complex) - CD4 <50 (disseminated); Candida (esophageal/oral thrush) - CD4 <100-200; Histoplasma, Coccidioides - endemic areas; Cryptosporidium (chronic diarrhea) - CD4 <100; JC virus → PML (progressive multifocal leukoencephalopathy) - CD4 <200; Kaposi's sarcoma (HHV-8); EBV → CNS lymphoma."
  },
  {
    "q": "Write about Chemical Carcinogenesis.",
    "a": "Stages: Initiation (irreversible DNA mutation), Promotion (reversible clonal expansion, no carcinogen), Progression (malignant conversion, additional mutations). Chemical classes: Direct-acting (no metabolism needed) - alkylating agents (nitrogen mustard, busulfan), acylating agents (β-propiolactone), cisplatin. Indirect-acting (require metabolic activation - procarcinogens → ultimate carcinogens by CYP450): PAHs (benzo[a]pyrene - tobacco → lung/skin), Aromatic amines (aniline → bladder), Azo dyes, Nitrosamines (gastric cancer), Aflatoxin B1 (HCC - TP53 codon 249 mutation), Benzene (leukemia). Mechanisms: DNA adducts, mutations in oncogenes (RAS) and tumor suppressor genes (TP53), epigenetic changes."
  },
  {
    "q": "Write short notes on Autonomy and Beneficence.",
    "a": "Autonomy: Patient's right to make informed decisions about their own healthcare. Components: Informed consent (disclosure, comprehension, voluntariness, competence, decision). Requires: Providing adequate information, ensuring understanding, respecting decision even if it disagrees with physician. Limitations: Emergency, incompetence, public health. Beneficence: Obligation to act in patient's best interest. Principle: 'Do good'. Components: Positive beneficence (provide benefit), Utility (balance benefit vs harm). Conflict with autonomy: Paternalism vs patient autonomy. Both are 4 pillars of medical ethics (Beauchamp & Childress): Autonomy, Beneficence, Non-maleficence, Justice."
  },
  {
    "q": "30/Male presented with massive splenomegaly. His total count was 2,35,000 cells per mm3 with preponderance of Neutrophilic precursors. Platelet count was 1,80,000 cells per mm3. What is your diagnosis? What is the molecular basis of this disease? Write about the morphological features. Classify myeloproliferative neoplasms.",
    "a": "Dx: CML (Chronic Myeloid Leukemia). Molecular basis: Philadelphia chromosome t(9;22)(q34;q11) → BCR-ABL1 fusion gene → constitutive tyrosine kinase activity → JAK-STAT, RAS, PI3K pathways → uncontrolled myeloid proliferation + anti-apoptosis. Morphology: Blood - leukocytosis (full myeloid spectrum, basophilia, eosinophilia), LAP score low. BM - hypercellular, myeloid:erythroid ratio >10:1, sea-blue histiocytes, Gaucher-like cells. Spleen - massive (extramedullary hematopoiesis). Classification of MPNs (WHO): CML (BCR-ABL1+), Polycythemia Vera (JAK2 V617F), Essential Thrombocythemia (JAK2/CALR/MPL), Primary Myelofibrosis (JAK2/CALR/MPL), CEL (chronic eosinophilic leukemia), MDS/MPN overlap."
  },
  {
    "q": "25 years female presented with malar rash on the face, fever, painful joints of fingers. What is your diagnosis? Write about the pathogenesis and diagnosis of the disease.",
    "a": "Dx: Systemic Lupus Erythematosus (SLE). Pathogenesis: Genetic predisposition (HLA-DR2/DR3, C2/C4 deficiency) → defective clearance of apoptotic cells → nuclear antigens exposed → loss of tolerance → autoreactive B & T cells → autoantibodies (ANA, anti-dsDNA, anti-Sm) → immune complex formation → complement activation → Type III hypersensitivity → tissue damage (kidney, skin, joints, serosal surfaces). Molecular: Defective NETosis, TLR7/9 activation by self-nucleic acids, interferons. Diagnosis: ACR/EULAR criteria (≥10 points). Tests: ANA (screening, sensitive), Anti-dsDNA (specific, correlates with activity), Anti-Sm (specific), Anti-Ro/La, Anti-phospholipid Ab, C3/C4 (decreased), CBC (pancytopenia), Coombs test, Urinalysis, Renal biopsy (WHO Class I-VI nephritis)."
  },
  {
    "q": "20 years female was diagnosed as extrapulmonary tuberculosis. She is very upset with the diagnosis. How will you support and educate her?",
    "a": "Support approach: Active listening, empathy, non-judgmental attitude, acknowledge fears (stigma, treatment duration). Education: Explain EPTB is NOT same as pulmonary TB (less/non-contagious), it is curable with complete treatment. DOTS (Directly Observed Treatment Short-course), treatment duration 6-9 months (2HRZE/4HR or longer based on site). Possible sites - lymph nodes, pleura, spine (Pott's), abdomen, CNS. Importance of treatment adherence (drug resistance risk). Address stigma and confidentiality. Nutritional support, follow-up schedule. Involve family, social support. Refer to counselor/DOTS center. Government free treatment (RNTCP/NTP). Screen close contacts."
  },
  {
    "q": "Write about disorders of pigments.",
    "a": "Endogenous pigments: Hemoglobin-derived: Hemosiderin (iron storage, brown-yellow, Prussian blue +ve, hemosiderosis vs hemochromatosis), Bilirubin (jaundice - prehepatic/hepatic/post-hepatic), Hematoidin (no iron, old hematomas), Hematin, Porphyrins. Melanin: Excess (melasma, Addison's disease, lentigo), Reduced (vitiligo, albinism). Lipochrome/Lipofuscin: 'Wear and tear' pigment, brown, perinuclear, lysosomes, seen in aging/atrophy. Exogenous pigments: Carbon (anthracosis - coal dust in macrophages), Tattoo pigments, Lead (gingival lead line), Silica, Asbestos (ferruginous bodies). Special: Bile pigments in cholestasis, Ochronosis (alkaptonuria - homogentisic acid)."
  },
  {
    "q": "What is the role of prostaglandins in inflammation?",
    "a": "Prostaglandins (PGs) in inflammation: Derived from arachidonic acid via COX-1/COX-2 pathway. Key PGs: PGE2 & PGI2 - vasodilation, increased vascular permeability (synergize with histamine/bradykinin), pain sensitization (lower threshold of nociceptors - hyperalgesia), fever (act on hypothalamus - raise set point). PGD2 - bronchoconstriction, chemotaxis of eosinophils. Thromboxane A2 (TXA2) - platelet aggregation, vasoconstriction. Prostacyclin (PGI2) - inhibits platelet aggregation, vasodilation. COX inhibition (NSAIDs/Aspirin) → anti-inflammatory, antipyretic, analgesic effects. COX-2 selective inhibitors (Celecoxib) - less GI side effects. Role in resolution and chronic inflammation modulation."
  },
  {
    "q": "What is cross matching? Types of cross matching and its importance.",
    "a": "Cross matching: Pre-transfusion compatibility test between donor RBCs and recipient serum/plasma. Types: Major crossmatch - Donor RBCs + Recipient serum (most important, detects recipient antibodies against donor antigens). Minor crossmatch - Recipient RBCs + Donor serum (detects donor antibodies against recipient antigens, less critical as donor plasma diluted). Electronic/Computer crossmatch - if previous 2 ABO/Rh typings concordant, no alloantibodies detected. Methods: Saline IS (immediate spin - detects IgM/ABO), 37°C albumin/LISS (detects IgG), AHG/Coombs phase (indirect Coombs - detects clinically significant antibodies). Importance: Prevents acute hemolytic transfusion reaction (ABO incompatibility = potentially fatal), detects minor antibodies, ensures compatibility."
  },
  {
    "q": "What are the types of carcinogens? Write about microbial carcinogens.",
    "a": "Types of carcinogens: Chemical (direct & indirect-acting), Physical (ionizing radiation, UV), Microbial (viral, bacterial, parasitic). Microbial carcinogens: Viruses: EBV → Burkitt's lymphoma (c-MYC translocation), NPC, HL, EBV+ DLBCL. HBV/HCV → HCC (cirrhosis + aflatoxin synergy, HBX protein). HPV 16/18 → cervical, anal, oropharyngeal Ca (E6→TP53 degradation, E7→Rb inactivation). HHV-8/KSHV → Kaposi's sarcoma, PEL. HTLV-1 → ATL (adult T-cell leukemia). MCPV → Merkel cell carcinoma. Bacteria: H. pylori → Gastric adenocarcinoma + MALT lymphoma (CagA, vacA virulence). Parasites: Schistosoma haematobium → bladder Ca (squamous). Opisthorchis viverrini/Clonorchis → cholangiocarcinoma."
  },
  {
    "q": "What do you know about stem cells? What is the role of stem cells in diseases?",
    "a": "Stem cells: Self-renewing, undifferentiated cells capable of producing differentiated progeny. Properties: Self-renewal, potency, asymmetric division. Types: Totipotent (fertilized egg), Pluripotent (ESCs - all 3 germ layers), Multipotent (tissue-specific - HSCs, MSCs), Unipotent (committed progenitors). Sources: Embryonic (ESC), Adult (bone marrow HSC, neural, intestinal crypts), Induced pluripotent (iPSC - Yamanaka factors: Oct4, Sox2, Klf4, c-Myc). Role in disease: Cancer stem cell hypothesis (CSCs - tumor initiation, resistance, metastasis - CD44+CD24- in breast). HSC transplant in hematologic malignancies. Therapeutic role: Regenerative medicine (diabetes, Parkinson's, cardiac repair), gene therapy, disease modeling. Niche: BM stroma, Wnt, Notch, Hedgehog signaling."
  },
  {
    "q": "Write about Von Willebrand disease.",
    "a": "VWD: Most common inherited bleeding disorder. Autosomal dominant (mostly). VWF: synthesized by endothelium & megakaryocytes, stored in Weibel-Palade bodies. Functions: Platelet adhesion (collagen-GpIb bridge), carrier for Factor VIII (protects from degradation). Types: Type 1 (partial quantitative decrease, AD, most common, 75%), Type 2 (qualitative defects) - 2A (decreased large multimers), 2B (gain-of-function, increased platelet binding), 2M, 2N (Normandy - decreased FVIII binding, AR); Type 3 (complete absence, AR, severe). Clinical: Mucocutaneous bleeding (epistaxis, menorrhagia, gum bleeding), post-procedural bleeding. Lab: Prolonged BT, prolonged APTT, low VWF antigen, low VWF activity (ristocetin cofactor assay - RICOF), low FVIII, normal PT. Treatment: DDAVP (Type 1), VWF concentrates."
  },
  {
    "q": "30 years female presented with menorrhagia. She has pallor, koilonychia. What will be the hematological findings in this patient?",
    "a": "Dx: Iron Deficiency Anemia (IDA). Hematological findings: CBC: Decreased Hb, low MCV (<80 fL), low MCH (<27 pg), low MCHC (<32 g/dL), elevated RDW (anisocytosis). Peripheral smear: Microcytic hypochromic RBCs (central pallor >1/3 diameter), poikilocytosis (pencil/cigar cells, target cells), anisopoikilocytosis, thrombocytosis (reactive). Reticulocyte count: Low (hypoproliferative). Serum iron: Decreased (<60 mcg/dL). Serum ferritin: Decreased (<12 ng/mL, most sensitive/specific). TIBC: Elevated (>360 mcg/dL). Transferrin saturation: <16%. Bone marrow: Depleted iron stores (absent Prussian blue staining), erythroid hyperplasia. Serum soluble transferrin receptor (sTfR): Elevated."
  },
  {
    "q": "What are the investigations required in a case of bleeding disorder?",
    "a": "Screening tests: CBC (platelets), Peripheral smear (platelet morphology, schistocytes), BT (bleeding time - platelet function), CT (clotting time - crude), PT (prothrombin time - extrinsic pathway, Factor VII, X, V, II, I), INR, APTT (intrinsic pathway, XII, XI, IX, VIII, X, V, II, I), Thrombin Time (fibrinogen function). Confirmatory/specific: Platelet function analysis (PFA-100), Factor assays (VIII, IX, XI, etc.), VWF antigen and activity (ristocetin cofactor), Fibrinogen level, D-dimer & FDP (DIC), Clot retraction test, Platelet aggregation studies, Mixing studies (distinguish factor deficiency from inhibitor), ELISA for anti-platelet antibodies. Special: RIPA (ristocetin-induced platelet aggregation - VWD 2B), Flow cytometry (HPN, Glanzmann's - CD41/61)."
  },
  {
    "q": "3 years male child had frontal bossing, pigeon chest, bowing of legs. What is the underlying dietary deficiency? What are the metabolic changes due to the deficiency? If seen in adults what is the clinical manifestation?",
    "a": "Dx: Rickets (Vitamin D deficiency in children). Metabolic changes: Decreased Vit D → decreased intestinal Ca & PO4 absorption → hypocalcemia → secondary hyperparathyroidism (PTH increase) → increased bone resorption + renal PO4 wasting (phosphaturia) → decreased Ca×PO4 product → defective mineralization of osteoid → epiphyseal widening, growth plate irregularity. Lab: Low 25-OH VitD, low Ca (may normalize with PTH), low PO4, elevated ALP, elevated PTH. In adults = Osteomalacia: Bone pain & tenderness (back, hips), proximal myopathy (difficulty climbing stairs), Looser zones (pseudo-fractures, milkman fractures) on X-ray pelvis/long bones, increased fracture risk, waddling gait. No growth plate changes (plates fused)."
  },
  {
    "q": "A patient is brought to casualty with multiple superficial and deep injuries. Patient is a known diabetic. Write in detail about the mechanism of healing and repair of injury. Discuss about the factors influencing the process of healing and expected complications.",
    "a": "Wound healing: Primary (clean sutured wound) vs Secondary (gaping wound) intention. Phases: Hemostasis (seconds-minutes: clot, vasoconstriction), Inflammation (1-3 days: PMNs then macrophages - 'chief conductor'), Proliferation (3-14 days: angiogenesis, fibroblast migration, collagen Type III, re-epithelialization, granulation tissue), Remodeling (weeks-months: Type III→Type I collagen, crosslinking, wound contraction by myofibroblasts, tensile strength). Growth factors: EGF, PDGF, FGF, VEGF, TGF-β. Factors impairing healing: Systemic (Diabetes - hyperglycemia impairs PMN function, angiopathy, neuropathy; Malnutrition - Vit C, zinc, protein; Steroids; Uremia; Old age; Anemia). Local (Infection, foreign body, wound tension, poor blood supply, hematoma, radiation, necrotic tissue). Complications: Infection, Keloid/hypertrophic scar, Contracture, Wound dehiscence, Chronic non-healing ulcer, Incisional hernia, Marjolin's ulcer (malignant transformation)."
  },
  {
    "q": "40 years old male with complaints of easy fatigability, history of fever and abdominal pain. On examination, there was hepatosplenomegaly and his WBC count was 1,08,000/cu.mm, Haemoglobin 8.8g/dl and platelet count 1,00,000/cu.mm. What is your probable diagnosis? Write in detail about the etiopathogenesis and other laboratory findings with relevant diagrams.",
    "a": "Dx: CML (Chronic Myeloid Leukemia). Etiopathogenesis: t(9;22) → BCR-ABL1 → constitutive TK → RAS/MAPK, JAK-STAT, PI3K-AKT activation → uncontrolled myeloid proliferation, impaired apoptosis (BCL-2 upregulation), genomic instability. Lab findings: CBC: TLC markedly elevated (myeloid predominance), mild-moderate anemia, thrombocytosis initially. Peripheral smear: Full myeloid spectrum (blasts <10% chronic phase), basophilia (hallmark), eosinophilia, large platelets. LAP/NAP score: Low/absent (helps differentiate from leukemoid reaction). Bone marrow: Hypercellular, M:E ratio >10:1, megakaryocytic hyperplasia, sea-blue histiocytes. Cytogenetics: Philadelphia chromosome (FISH/karyotype). Molecular: BCR-ABL1 by RT-PCR (quantitative). Biochemistry: Elevated uric acid, LDH, Vit B12, B12-binding proteins."
  },
  {
    "q": "Write about Chemotaxis.",
    "a": "Chemotaxis: Directed migration of leukocytes along concentration gradient of chemotactic agents (chemoattractants). Exogenous: Bacterial products (fMLP - N-formyl-methionyl peptides), Lipopolysaccharide (LPS). Endogenous: C5a (complement), Leukotriene B4 (LTB4 - most potent for neutrophils), IL-8/CXCL8, Fibrin degradation products, Platelet-activating factor (PAF). Mechanism: Chemoattractant binds GPCR on leukocyte → G-protein activation → PI3K → PIP3 → Rac/Rho GTPases → actin polymerization at leading edge (lamellipodia) → pseudopod formation → directional movement. Defects: Chediak-Higashi syndrome (microtubule defect), Leukocyte adhesion deficiency (LAD - β2 integrin defect, no CD18). Clinical significance: Acute inflammation recruitment, abscess formation."
  },
  {
    "q": "Write about Turner's syndrome.",
    "a": "Turner Syndrome: 45,X0 (monosomy X) - most common sex chromosome abnormality in females. Karyotype: 45,X (50%), mosaicism 45,X/46,XX, isochromosome Xq, ring chromosome X. Mechanism: Nondisjunction during meiosis (paternal origin more common) or postzygotic mitotic error. Features: Short stature (most common), Primary amenorrhea, Streak gonads (gonadal dysgenesis - no follicles → infertility), Webbed neck (pterygium colli), Low posterior hairline, Shield chest, Widely spaced nipples, Lymphedema (hands/feet - neonatal), Cubitus valgus, Horseshoe kidney, Bicuspid aortic valve/coarctation of aorta. Intelligence: Usually normal. Diagnosis: Karyotype. Hormones: Elevated FSH/LH, low estrogen. Treatment: Growth hormone (height), Estrogen replacement (puberty induction, osteoporosis prevention), Regular cardiac/renal screening."
  },
  {
    "q": "Describe in detail the events of invasion and metastasis in neoplasia.",
    "a": "Invasion & Metastasis (Hallmarks of Cancer): Steps in metastatic cascade: 1) Local invasion - Loss of E-cadherin (adhesion) → Epithelial-Mesenchymal Transition (EMT, Snail/Slug TFs) → degradation of basement membrane (MMP-2, MMP-9) → invasion into stroma. 2) Intravasation - entry into blood/lymph vessels (active process). 3) Survival in circulation - resistance to anoikis, immune evasion (PD-L1), platelet aggregation (protection). 4) Arrest at distant site - organ-specific adhesion molecules (organ tropism - 'seed and soil' hypothesis, Paget). 5) Extravasation - exit from vessel. 6) Colonization/Micrometastasis - pre-metastatic niche formation (VEGF, LOX), angiogenesis (VEGF), proliferation. Key molecules: Integrins, CD44, CXCR4/CXCL12 (breast → bone marrow), HGF/c-MET. Routes: Lymphatic (carcinomas), Hematogenous (sarcomas, hepatocellular, renal cell), Seeding of body cavities (ovarian), Perineural."
  },
  {
    "q": "Write about Lab diagnosis of DIC (Disseminated Intravascular Coagulation).",
    "a": "DIC Lab Diagnosis: Causes: Sepsis (#1), Obstetric emergencies (amniotic fluid embolism, abruptio placentae, eclampsia), Trauma, Malignancy (APML - M3, mucinous adenocarcinoma), Transfusion reactions, Snake bite. Lab findings (consumption of clotting factors + platelets + fibrinogen): Thrombocytopenia (decreased platelets), Prolonged PT and APTT, Hypofibrinogenemia (<150 mg/dL - key marker), Elevated D-dimer (elevated cross-linked fibrin degradation products - most sensitive), Elevated FDP (fibrin degradation products), Peripheral smear: Schistocytes (helmet cells, fragmented RBCs - microangiopathic hemolytic anemia), Decreased Factor V & VIII. ISTH Scoring (overt DIC): Platelets, PT, Fibrinogen, D-dimer/FDP → score ≥5 = overt DIC. Paradox: Simultaneous thrombosis + bleeding."
  },
  {
    "q": "What is informed consent? Discuss the components of an informed consent.",
    "a": "Informed consent: Legal and ethical process by which a patient voluntarily agrees to a medical procedure/treatment after being fully informed. Ethical basis: Autonomy, Beneficence, Non-maleficence. Components (VICDEC): Voluntariness - free from coercion/undue influence; Information/Disclosure - diagnosis, nature of procedure, risks & benefits, alternatives (including no treatment), likely outcomes; Comprehension/Understanding - patient understands (assess through teach-back); Decision-making capacity/Competence - adult, mentally competent; Expression/Decision - patient makes and communicates decision; Consent - written/verbal (written for surgery, high-risk procedures). Special situations: Emergency (implied consent), Minors (parental consent + assent), Incompetent patients (surrogate/legal guardian). Exceptions: Emergency, Waiver by patient, Therapeutic privilege (rare, controversial)."
  },
  {
    "q": "Write in detail about pathogenesis and investigation of sickle cell disease.",
    "a": "Sickle cell disease: Autosomal recessive, HBB gene mutation (codon 6: Glu→Val) → HbS. Pathogenesis: Deoxygenation → HbS polymerization → tactoids (rigid polymers) → RBC sickling → Membrane damage (irreversible sickle cells) → 3 consequences: Hemolysis (intravascular + extravascular, Hb 6-8 g/dL), Vaso-occlusion (obstruction by rigid sickled cells → ischemia/pain crises, AVN, stroke, ACS, priapism, renal papillary necrosis), Splenic sequestration → autosplenectomy (functional asplenia → susceptibility to encapsulated organisms). Protective effect of HbF (inhibits sickling) and heterozygous trait (malaria resistance). Investigations: Sickle solubility test (Dithionite/Metabisulfite - screening), Hb electrophoresis (HbS 80-95%, HbF 2-20%, no HbA - confirmatory, cellulose acetate pH 8.4 + citrate agar pH 6.2), HPLC (gold standard), Peripheral smear (sickle cells, target cells, Howell-Jolly bodies post-autosplenectomy), Prenatal diagnosis (PCR, RFLP)."
  },
  {
    "q": "27 years old female, one week after normal delivery presented with complaints of dyspnoea, irritability with bleeding per vaginum admitted in postnatal ward. On examination she had hypotension and increased pulse rate. What is your probable diagnosis? What are the causes and other investigations needed to confirm the diagnosis?",
    "a": "Dx: DIC (Disseminated Intravascular Coagulation) - postpartum. Causes (obstetric): Retained products of conception, Endometritis, Postpartum hemorrhage (PPH), Amniotic fluid embolism, Abruptio placentae, Eclampsia/HELLP syndrome, Sepsis. Investigations: CBC (thrombocytopenia), PT & APTT (prolonged), Fibrinogen (decreased), D-dimer (elevated), FDP (elevated), Peripheral smear (schistocytes), Blood culture (if sepsis suspected), LFT (HELLP), Urine (hemoglobinuria), Coagulation factor assays (V, VIII decreased), ISTH DIC score. Management triggers: Fresh frozen plasma (FFP), Cryoprecipitate (fibrinogen), Platelet transfusion, Treat underlying cause (oxytocin, antibiotics, surgical evacuation)."
  },
  {
    "q": "Write about Leukemoid reaction.",
    "a": "Leukemoid reaction: Marked leukocytosis (TLC >50,000/mm3) in response to systemic disease (not leukemia). Causes: Bacterial infections (TB, sepsis, pertussis), Viral (CMV, EBV), Parasitic, Severe hemolysis, Burns, Malignancy, Drug reactions (G-CSF), Postsplenectomy. Morphology: Neutrophilic (most common) or lymphocytic (viral infections - reactive lymphocytes/Downey cells in EBV) or eosinophilic. Features: Toxic granulation, Döhle bodies, vacuolization in neutrophils (reactive changes). Key distinguishing features from CML: LAP/NAP score - HIGH in LR (low in CML); No Philadelphia chromosome/BCR-ABL1 in LR; Splenomegaly less pronounced in LR; Basophilia absent in LR; No full myeloid spectrum in LR; Resolves with underlying cause. Clinical significance: Must not be confused with CML."
  },
  {
    "q": "Write about Burkitt's lymphoma.",
    "a": "Burkitt's lymphoma: Highly aggressive B-cell NHL. Molecular hallmark: c-MYC translocation - t(8;14)(q24;q32) [most common, 80%], or t(2;8), t(8;22) → IgH/IgL-MYC fusion → uncontrolled cell proliferation. EBV association: Endemic (African) form - 95% EBV+; Sporadic - 15-20% EBV+; HIV-associated - variable. Forms: Endemic (African) - jaw/facial bones (children 4-7 yrs); Sporadic - ileocecal/abdominal mass (young adults, Western countries); Immunodeficiency-associated (HIV). Morphology: Intermediate-sized lymphocytes, high mitotic index, 'starry-sky' pattern (tingible body macrophages phagocytosing apoptotic debris). Immunophenotype: CD20+, CD10+, BCL6+, BCL2-, Ki-67 ~100% (highest proliferation rate of any tumor). Diagnosis: Biopsy, FISH (MYC), PET-CT, BM biopsy. Treatment: Intensive chemotherapy (R-CODOX-M/IVAC), very high cure rate."
  },
  {
    "q": "Enumerate the various carcinogenic agents. Write in detail about the process of Carcinogenesis in Carcinoma cervix.",
    "a": "Carcinogenic agents: Chemical (PAHs, nitrosamines, aromatic amines, alkylating agents, aflatoxin, benzene), Physical (ionizing radiation - UV/X-ray/gamma, asbestos, chronic irritation), Microbial (HPV, HBV, HCV, EBV, HTLV-1, H. pylori, Schistosoma). Carcinogenesis in Cervical Carcinoma: High-risk HPV (16, 18, 31, 33, 45) - Sexual transmission. Viral integration into host genome → E6 protein (binds & degrades TP53 via ubiquitin-proteasome - loss of apoptosis/cell cycle arrest) + E7 protein (binds Rb → releases E2F → uncontrolled S-phase entry). Progression: Normal → CIN I (koilocytes, mild dysplasia) → CIN II → CIN III/CIS → Invasive carcinoma. Cofactors: Multiple sexual partners, early sexual debut, smoking (tobacco carcinogens in cervical mucus), immunosuppression (HIV), OCP, C. trachomatis. Screening: Pap smear (exfoliative cytology, Bethesda system), colposcopy, HPV DNA testing. Prevention: HPV vaccine (Gardasil - 9-valent)."
  },
  {
    "q": "26 years old multipara presented in Obstetric OPD with complaints of easy fatiguability and breathlessness. On evaluation her Haemoglobin level - 6.2 g/dl, serum iron level - 40 mcg/dl. What is the probable cause? Write about the pathogenesis and other investigations needed to confirm the diagnosis.",
    "a": "Dx: Iron Deficiency Anemia (IDA) - secondary to multiparity (recurrent pregnancy - increased iron demand). Probable cause: Chronic blood loss (menorrhagia, multiple pregnancies), Increased demand (multiparity, lactation), Inadequate dietary intake. Pathogenesis: Negative iron balance → Depleted stores (↓ ferritin) → Transport iron depleted (↓ serum iron, ↑ TIBC) → Iron deficient erythropoiesis (↑ sTfR, ↓ Hb per RBC) → Iron deficiency anemia (microcytic hypochromic). Investigations: CBC (microcytic hypochromic, ↑ RDW), Peripheral smear (pencil cells, target cells, anispoikilocytosis), Serum ferritin (<12 ng/mL - earliest depleted), Serum iron (↓), TIBC (↑ >360 μg/dL), Transferrin saturation (<16%), Reticulocyte count (low for degree of anemia), Bone marrow iron staining (absent hemosiderin - Prussian blue). Stool for occult blood, Upper GI endoscopy (if occult loss suspected)."
  },
  {
    "q": "Write about the pathogenesis of cystic fibrosis.",
    "a": "Cystic Fibrosis: Autosomal recessive, CFTR gene (chromosome 7q31.2). Most common mutation: ΔF508 (deletion of phenylalanine at position 508 - protein misfolding → ER retention → degradation). CFTR: cAMP-regulated chloride channel. Pathogenesis: Mutant CFTR → defective Cl⁻ transport → decreased Cl⁻ secretion → Na⁺ hyperabsorption (through ENaC) → osmotic water reabsorption → thick, viscid secretions. Effects by organ: Lung (chronic obstruction by thick mucus → Pseudomonas/S. aureus infection → bronchiectasis, lung destruction), Pancreas (ductal obstruction → acinar atrophy, fibrosis → exocrine insufficiency → malabsorption, fat-soluble vitamin deficiency; endocrine insufficiency → CF-related diabetes), Liver (focal biliary cirrhosis), Intestine (meconium ileus in neonates, distal intestinal obstruction), Reproductive (vas deferens absence → male infertility; thick cervical mucus → female subfertility), Sweat glands (high Cl⁻ in sweat - diagnostic). Diagnosis: Sweat chloride test (>60 mEq/L), Genetic testing (CFTR mutations)."
  },
  {
    "q": "Write about Vitamin A deficiency - Causes and Pathology.",
    "a": "Vitamin A: Fat-soluble, stored in liver (stellate cells). Active forms: Retinol (transport), Retinal (vision), Retinoic acid (gene expression via nuclear RAR/RXR receptors). Causes of deficiency: Malnutrition (poor diet, low green leafy vegetables/carrots/liver), Malabsorption (fat malabsorption - cholestasis, celiac, cystic fibrosis, IBD), Liver disease (reduced storage/transport - low RBP), Increased demand (pregnancy, measles, diarrhea). Pathology: Eye (most specific): Night blindness (earliest - rhodopsin synthesis requires retinal), Xerophthalmia (conjunctival/corneal dryness - Bitot's spots = keratinized squamous metaplasia of conjunctiva), Keratomalacia (corneal ulceration + necrosis → blindness - WHO staging). Squamous metaplasia of epithelium (respiratory - predisposes to infection, urinary - stones). Impaired immunity (B & T cell function). Reproductive failure. Epiphyseal growth plate thickening. Diagnosis: Serum retinol, dark adaptation test. Treatment: High-dose Vit A (WHO protocol)."
  },
  {
    "q": "Write about Klinefelter syndrome.",
    "a": "Klinefelter syndrome: 47,XXY (most common - 80%); variants: 48,XXXY; 48,XXYY; mosaics (46,XY/47,XXY). Mechanism: Nondisjunction during meiosis (maternal meiosis I most common) or postzygotic error. Pathogenesis: Extra X → inactivation (Barr body present) but some genes escape → overexpression affects testicular development → hyalinization of seminiferous tubules → azoospermia. Features: Tall stature (long legs), Small firm testes (hyalinized tubules), Azoospermia → infertility, Gynecomastia (↑ risk breast cancer), Sparse body hair, Female fat distribution, Mild learning disability/behavioral issues, Low testosterone, Elevated FSH/LH. Diagnosis: Karyotype (47,XXY), semen analysis (azoospermia), hormones (↑FSH/LH, ↓testosterone). Treatment: Testosterone replacement (male secondary characteristics, bone density, mood), ART (testicular sperm extraction - TESE + ICSI) for fertility."
  },
  {
    "q": "Write about the morphologic changes of reversible injury.",
    "a": "Reversible injury (sublethal cell injury): Changes are reversible upon removal of stimulus. Causes: Ischemia (early), Toxins, Infections, Physical agents. Morphological changes: Gross: Organ appears pale, slightly swollen. Light microscopy: Cellular swelling (earliest, most common) - hydropic change/vacuolar degeneration (water accumulates in cytoplasm), Fatty change (steatosis - especially liver, heart, kidney - lipid vacuoles), Myelin figures (EM - whorled membrane structures). EM changes: Plasma membrane blebbing, Mitochondria swelling (amorphous densities, loss of cristae), Dilatation of ER (ribosome detachment), Nuclear changes (clumping of chromatin, reversible). Key markers: Cytoplasmic eosinophilia (loss of RNA, protein denaturation). Key: Nuclear integrity maintained (cell death not yet committed), organelle changes reversible. Distinguished from irreversible injury by: intact cell membrane, absence of karyolysis/karyorrhexis."
  },
  {
    "q": "Blood transfusion is advised for a post tonsillectomy patient. Immediately after starting the transfusion, patient complains of chills with rigors. What is the diagnosis and how will you manage the patient?",
    "a": "Dx: Febrile Non-Hemolytic Transfusion Reaction (FNHTR) - most common transfusion reaction. Cause: Recipient antibodies against donor leukocyte antigens (HLA) or cytokines accumulated in stored blood. Management: STOP transfusion immediately. Maintain IV access. Vital signs monitoring. Send: blood bag to blood bank + patient blood (re-crossmatch, direct Coombs, repeat ABO/Rh), urine (hemoglobin). Rule out acute hemolytic reaction (most important). Treatment: Antipyretics (Paracetamol), Antihistamines. If fever settles and hemolysis ruled out, transfusion may be restarted with fresh unit. Future prevention: Leukodepleted/filtered blood products. Report to blood bank. Note: If rigors with fever occur, must first rule out acute hemolytic reaction (potentially fatal) and bacterial contamination (septic reaction) before diagnosing FNHTR."
  },
  {
    "q": "Write about blood smear and bone marrow findings in Megaloblastic anemia.",
    "a": "Megaloblastic anemia: Cause - Vit B12/Folate deficiency → impaired DNA synthesis → nuclear-cytoplasmic asynchrony. Peripheral blood smear: Macrocytic/Megalocytic anemia (MCV >100 fL), Macro-ovalocytes (oval macrocytes - pathognomonic), Hypersegmented neutrophils (≥5 lobes in >5% neutrophils OR any neutrophil with ≥6 lobes - most specific early finding), Anispoikilocytosis, Leukopenia + thrombocytopenia (pancytopenia in severe cases), Teardrop cells, Howell-Jolly bodies. Bone marrow: Hypercellular (erythroid hyperplasia), Megaloblasts (large cells with immature 'open chromatin' nucleus but mature hemoglobinized cytoplasm = nuclear-cytoplasmic asynchrony), Giant metamyelocytes & band neutrophils (hallmark of megaloblastic change in myeloid series), Hypersegmented megakaryocytes, M:E ratio reversed (<1:1). Biochemistry: Elevated LDH, elevated indirect bilirubin (ineffective erythropoiesis)."
  },
  {
    "q": "Write about Type II hypersensitivity reaction.",
    "a": "Type II = Cytotoxic/Antibody-dependent Cytotoxicity. Mechanism: IgG or IgM antibodies bind to cell-surface antigens or ECM components → cell destruction. Mechanisms of destruction: 1) Complement activation (C1q binding → classical pathway → MAC → osmotic lysis), 2) ADCC (Antibody-dependent cell-mediated cytotoxicity - NK cells/macrophages via Fc receptors), 3) Opsonization & phagocytosis (C3b + IgG → macrophage Fc/complement receptors), 4) Antibody-mediated cellular dysfunction (without cell destruction - stimulatory: Graves' disease with TSH-R Ab; inhibitory: Myasthenia Gravis with AChR Ab). Examples: Autoimmune hemolytic anemia, ITP, Goodpasture syndrome (anti-GBM), ABO-incompatible transfusion reaction, Erythroblastosis fetalis (Rh), Pemphigus vulgaris (anti-desmoglein), Graves' disease, Myasthenia gravis, Drug-induced hemolytic anemia."
  },
  {
    "q": "What is the screening procedure to be done for a 42 years old female presented in Gynaecology OPD with the complaints of leucorrhea? Describe in detail regarding the screening procedure.",
    "a": "Screening: Pap smear (Papanicolaou test) for cervical cancer screening. Collection: Patient instructions (no intercourse/douching/vaginal medications 48 hrs prior, avoid during menstruation). Position: Lithotomy. Equipment: Cusco's speculum, Ayre's spatula (ectocervix) + endocervical brush/cytobrush. Sites: Transformation zone (squamocolumnar junction) is key. Conventional Pap smear: Smear on glass slide, fix immediately (95% ethanol/spray fixative), Papanicolaou staining. Liquid-based cytology (LBC/ThinPrep): Rinse brush in vial → better cell preservation, less obscuring material, allows reflex HPV testing. Bethesda reporting system (2014): NILM (Normal), ASC-US, ASC-H, LSIL (CIN I), HSIL (CIN II/III), Squamous cell carcinoma, AGC, Adenocarcinoma. Additional test: Co-testing with HPV DNA (high-risk types 16/18). Management based on result: Colposcopy for abnormal, Biopsy if suspicious, LEEP/cone biopsy if CIN II/III confirmed."
  },
  {
    "q": "Define embolism and write about pulmonary embolism.",
    "a": "Embolism: Intravascular mass (solid, liquid or gas) carried in blood to a site distant from origin, causing obstruction. Types of emboli: Thromboembolism (most common), Fat, Air/gas, Amniotic fluid, Tumor, Septic, Foreign body. Pulmonary Embolism: 95% originate from DVT of lower extremity (femoral/iliac/popliteal veins). Risk factors: Virchow's triad (stasis - immobility; hypercoagulability - thrombophilia, OCP, malignancy; endothelial injury - surgery, trauma). Pathophysiology: Embolus lodges in pulmonary artery → mechanical obstruction → increased PVR → right heart strain (cor pulmonale). Clinical: Massive PE (>60% occlusion) → sudden death, severe hypoxia, shock. Moderate - pleuritic chest pain, dyspnea, hemoptysis, pleural rub. Small/multiple - pulmonary hypertension. Pulmonary infarction: rare (dual blood supply via bronchial arteries). Morphology: Hemorrhagic wedge-shaped infarct (if concurrent bronchial artery insufficiency). Diagnosis: D-dimer, CT pulmonary angiography (CTPA - gold standard), V/Q scan, Echo (RV strain), ABG, ECG (S1Q3T3, sinus tachycardia). Treatment: Anticoagulation (heparin→warfarin/DOAC), Thrombolysis (massive PE), Embolectomy."
  },
  {
    "q": "What is empathy? What is the role of empathy in care of patients?",
    "a": "Empathy: Ability to understand and share the feelings of another person - cognitive (understanding patient's perspective intellectually) and affective (feeling the emotional resonance). Differs from sympathy (feeling sorry for) and pity. Role in patient care: Therapeutic alliance - builds trust, rapport, open communication. Improves history taking - patients share more symptoms, concerns. Increases treatment adherence - patient feels understood, more likely to follow advice. Reduces patient anxiety and distress. Improves diagnostic accuracy - less anchoring bias. Patient satisfaction and better outcomes. Prevents burnout (professional fulfillment). Medico-legal protection (good relationship reduces complaints). How to demonstrate: Active listening, maintaining eye contact, reflective statements ('That must be difficult'), acknowledging feelings, open body language, appropriate touch, sitting at same level. Barriers: Time pressure, stress, emotional detachment (over-professionalism), cultural differences. Communication in MBBS: Part of AETCOM curriculum."
  },
  {
    "q": "A 40-year-old female complaints of loss of weight, massive splenomegaly with very high total count. What is your probable diagnosis? What are the characteristic peripheral smear findings? Describe the course of the disease and possible complications. What is the genetic abnormality involved and brief about lab diagnosis?",
    "a": "Dx: Chronic Myeloid Leukemia (CML). Peripheral smear findings: Marked leukocytosis with full myeloid spectrum (myeloblasts <10% in chronic phase, myelocytes, metamyelocytes predominant), Basophilia (hallmark), Eosinophilia, Thrombocytosis (early), normocytic anemia, Low LAP/NAP score (<20 - important differentiator). Course & Complications: Chronic phase (3-4 yrs, asymptomatic-minimal symptoms) → Accelerated phase (>10% blasts, cytogenetic evolution, increasing splenomegaly, anemia, thrombocytopenia, increasing basophils >20%) → Blast crisis/Acute transformation (>20% blasts = AML 70% or ALL 30%; median survival 3-6 months). Complications: Leukostasis, Hyperuricemia/Gout, Splenic infarct, Priapism (leukostasis). Genetic abnormality: t(9;22)(q34;q11) → Philadelphia chromosome → BCR-ABL1 (p210 fusion protein). Lab diagnosis: FISH/Karyotype (Ph chromosome), RT-PCR (BCR-ABL1 quantitative - monitoring response), CBC, LAP score, Bone marrow (hypercellular, myeloid hyperplasia, sea-blue histiocytes)."
  },
  {
    "q": "A 40-year-old male presented with history of high-grade fever. Patient had weak rapid pulse, hypotension and tachypnea, cold clammy and cyanotic skin. Blood culture reveals Gram negative bacterial infection. What is your diagnosis? Explain the pathogenesis and morphology with examples. Brief about other possible causes of your diagnosis.",
    "a": "Dx: Septic Shock (Gram-negative). Pathogenesis: LPS/Endotoxin (lipid A component) → binds CD14 + TLR4 (with LBP & MD2) on macrophages → NF-κB activation → TNF-α, IL-1β, IL-6, IL-12 release → Cytokine storm → iNOS activation → NO overproduction → vasodilation (decreased SVR) + Endothelial injury → increased vascular permeability + Procoagulant state (DIC) → decreased tissue perfusion → MODS. Compensatory: epinephrine, vasopressin, cortisol. Decompensation → irreversible organ failure. Morphology (MODS): Lung - ARDS (DAD - hyaline membranes, diffuse alveolar damage), Kidney - ATN (coagulative tubular necrosis), Adrenal - Waterhouse-Friderichsen syndrome (hemorrhage), Liver - centrilobular necrosis, Brain - hypoxic encephalopathy. Other causes of septic shock: Gram-positive (Staph, Strep - toxins: TSST-1, Streptolysin), Fungi (Candida - in immunosuppressed), Viruses (rarely). Other types of distributive shock: Anaphylactic, Neurogenic, Adrenal crisis."
  },
  {
    "q": "Define necrosis and write a note on caseation necrosis.",
    "a": "Necrosis: Pathological cell death resulting from exogenous injurious stimuli, characterized by cell membrane disruption, enzyme leakage, inflammation, and altered nuclear morphology (karyolysis, karyorrhexis, pyknosis). Always pathological (unlike apoptosis). Caseation necrosis: Characteristic of Mycobacterium tuberculosis infection (also fungi - Histoplasma, Coccidioides; rarely sarcoid). Gross: Soft, crumbly, cheese-like (caseum = Latin for cheese), yellowish-white appearance. Micro: Amorphous granular eosinophilic material, loss of all cellular architecture (no 'ghost cells' unlike coagulative necrosis), surrounded by granuloma (epithelioid macrophages + Langhans giant cells + lymphocytes). Significance: Macrophages unable to digest mycobacteria → liquefaction due to proteolytic enzymes → if liquefied material enters bronchus → cavity (open TB, highly infectious) → miliary spread if enters blood vessel. Ziehl-Neelsen stain for AFB. Calcification on healing."
  },
  {
    "q": "Classify Amyloidosis and describe the morphology of spleen in amyloidosis.",
    "a": "Classification: Systemic: AL (primary - immunocyte dyscrasias, free light chains - plasma cell myeloma, MGUS); AA (secondary/reactive - chronic inflammation - TB, RA, IBD, FMF; SAA protein); ATTR (familial transthyretin - autosomal dominant, TTR mutations; senile systemic amyloidosis - wild-type TTR); Aβ2M (dialysis-associated - β2-microglobulin). Organ-specific: Aβ (Alzheimer's, Down's - cerebral plaques); AIAPP (type 2 DM - pancreatic islets); Atrial natriuretic peptide (cardiac). Hereditary: Finnish type (gelsolin), British/Danish type. Spleen morphology: Two patterns: 1) Sago spleen - deposits in splenic follicles (lymphoid follicles) → translucent gray nodules resembling sago (tapioca) grains, seen with Congo red as discrete nodules; seen in early/reactive AA amyloid. 2) Lardaceous spleen - diffuse deposition in splenic sinuses/red pulp → homogeneous waxy gray-pink enlarged spleen, 'lard-like' appearance, seen in advanced/AL amyloid. Congo red stain → apple-green birefringence under polarized light."
  },
  {
    "q": "Write about Fluorescence in Situ Hybridization (FISH).",
    "a": "FISH: Cytogenetic technique using fluorescently labeled DNA probes that hybridize to complementary target sequences on chromosomes. Principle: Denature target DNA (interphase or metaphase chromosomes) + denatured fluorescent probe → hybridization → visualization under fluorescence microscope. Types of probes: Locus-specific (gene rearrangements, deletions - e.g., BCR-ABL1, RB1), Centromeric (chromosome enumeration - aneuploidy detection), Whole chromosome paint (translocations), Telomeric. Applications in pathology: Hematologic malignancies (BCR-ABL1 in CML/ALL, ETV6-RUNX1 in B-ALL, MYC/BCL2/BCL6 in lymphomas), Solid tumors (HER2/NEU amplification in breast cancer, EGFR in NSCLC, ALK rearrangement, ERG in prostate cancer), Prenatal diagnosis (trisomies 13,18,21, sex chromosomes - rapid FISH), Tumor classification, Prognosis assessment. Advantages over karyotype: Performed on interphase nuclei (no cell culture needed), Faster (24-48 hrs), More sensitive, Can be done on FFPE tissue. Limitation: Targeted (only detects what probe is designed for)."
  },
  {
    "q": "Write briefly about Idiopathic Thrombocytopenic Purpura, etiology, morphology and investigatory findings.",
    "a": "ITP (Immune Thrombocytopenic Purpura): Acquired immune-mediated thrombocytopenia without underlying cause. Forms: Acute (children, post-viral, self-limiting); Chronic (adults, >12 months, female predominance). Etiology: Autoimmune - IgG autoantibodies (anti-GpIIb/IIIa, anti-GpIb/IX) → opsonized platelet destruction by splenic macrophages (Fc-mediated phagocytosis) + impaired megakaryopoiesis + T-cell mediated platelet destruction. Triggers: Viral infections, H. pylori, drugs, SLE, HIV, HCV. Morphology: Spleen - mild enlargement (not massive), germinal center hyperplasia, sinusoidal congestion, macrophage hyperplasia. Bone marrow - increased megakaryocytes (hyperplasia, may appear immature/dysmorphic). Skin - petechiae, purpura, bruising. Investigatory findings: Thrombocytopenia (isolated - platelets <100,000), Large/giant platelets (megathrombocytes), Normal PT & APTT, Prolonged bleeding time, Bone marrow (increased megakaryocytes), Anti-platelet antibodies (not routinely used), Platelet survival time decreased, Rule out secondary causes (ANA, HIV, HCV serology, H. pylori)."
  },
  {
    "q": "Write about Amniotic fluid embolism.",
    "a": "Amniotic fluid embolism (AFE): Rare, catastrophic obstetric emergency. Entry of amniotic fluid (containing fetal cells, debris, lanugo, meconium, mucin, vernix) into maternal circulation through tears in uterine/cervical veins. Pathogenesis: 2 phases: Phase 1 - Pulmonary vasospasm + bronchospasm (humoral mediators - TXA2, histamine, bradykinin, endothelin) → acute right heart failure + hypoxia. Phase 2 - Left heart failure → pulmonary edema + DIC (tissue factor in amniotic fluid → coagulation activation → consumption coagulopathy → hemorrhage). Triggers: Labor/delivery, C-section, amniocentesis, uterine manipulation. Clinical: Classical triad - hypoxia + hypotension + coagulopathy/DIC. Sudden cardiovascular collapse during/after delivery. Morphology: Lung histology - fetal squames, lanugo, mucin, vernix in pulmonary vessels (confirmatory but not always diagnostic). Diagnosis: Clinical exclusion, tryptase, zinc coproporphyrin, sialyl Tn antigen. Management: Supportive (ABC), ECMO, manage DIC (FFP, cryo, platelets), delivery of fetus if still in utero."
  },
  {
    "q": "Discuss in detail about Paroxysmal Nocturnal Hemoglobinuria (PNH).",
    "a": "PNH: Acquired clonal disorder of hematopoietic stem cell. Pathogenesis: Somatic mutation in PIG-A gene (X-linked) → deficient GPI (glycosylphosphatidylinositol) anchor biosynthesis → loss of GPI-anchored complement regulatory proteins: CD55 (DAF - Decay Accelerating Factor) + CD59 (MIRL - inhibits MAC assembly) → complement-mediated RBC lysis + platelet activation. Triad: Hemolytic anemia (intravascular, complement-mediated), Thrombosis (most serious complication - portal, hepatic veins - Budd-Chiari, cerebral veins; platelet activation by complement), Cytopenias (aplastic marrow component - PNH clone from aplastic anemia). Clinical: Hemoglobinuria (classic - dark urine in morning, not exclusively nocturnal), fatigue, abdominal pain (smooth muscle dystonia - NO scavenging by free Hb), dysphagia. Diagnosis: Flow cytometry (CD55, CD59 deficiency on RBCs and WBCs - gold standard), Ham's test (acid hemolysis - now replaced by flow), Sucrose lysis test. Treatment: Eculizumab (anti-C5 monoclonal antibody - blocks terminal complement), Ravulizumab, Allogeneic SCT (curative)."
  },
  {
    "q": "Write about lab diagnosis of iron deficiency anemia.",
    "a": "IDA Lab Diagnosis (stages - earliest to latest): Stage 1 (Storage iron depletion): Serum ferritin decreased (<12 ng/mL - most sensitive early marker), bone marrow iron absent (Prussian blue negative). Stage 2 (Transport iron depletion): Serum iron decreased (<60 μg/dL), TIBC increased (>360 μg/dL), Transferrin saturation decreased (<16%), Serum soluble transferrin receptor (sTfR) increased. Stage 3 (Iron deficient erythropoiesis): Reticulocyte Hb content decreased, Zinc protoporphyrin increased. Stage 4 (IDA): Hemoglobin decreased, MCV decreased (<80 fL), MCH decreased (<27 pg), MCHC decreased (<32 g/dL), RDW increased (anisocytosis). Peripheral smear: Microcytic hypochromic RBCs, increased central pallor (>1/3 RBC diameter), Pencil/Cigar cells (elongated), Target cells, Anisopoikilocytosis, Thrombocytosis (reactive). Bone marrow: Erythroid hyperplasia, absent stainable iron (Prussian blue = Perl's test - gold standard for iron stores). Distinguish from other microcytic anemias (Thalassemia, ACD, Sideroblastic anemia)."
  },
  {
    "q": "Write in detail about Chemical Carcinogenesis.",
    "a": "Chemical Carcinogenesis - Stages: 1) Initiation: Irreversible DNA mutation by carcinogen, non-lethal, no morphologic change, permanent. 2) Promotion: Reversible clonal expansion of initiated cells by promoters (not carcinogenic alone), reversible if promoter removed. 3) Progression: Additional mutations → malignant conversion, irreversible, genomic instability. Classes: Direct-acting (ultimate carcinogens, no metabolism needed): Alkylating agents (busulfan, nitrogen mustard - cross-link DNA), β-propiolactone, Dimethylsulfate. Indirect-acting (procarcinogens → metabolic activation by CYP450/CYP1A1 → ultimate carcinogen): PAHs (benzo[a]pyrene in cigarette smoke → lung/skin/bladder Ca), Aromatic amines (2-naphthylamine, aniline dyes → bladder Ca), Nitrosamines (pickled/processed food → gastric Ca), Aflatoxin B1 (Aspergillus flavus, contaminated grains → HCC - TP53 Arg249Ser mutation), Benzene (leukemia/AML), CCl4 (liver damage). Mechanisms: DNA adduct formation (G-T or G-A mispairing), Oncogene activation (RAS mutations - point mutations), Tumor suppressor gene inactivation (TP53), Epigenetic (methylation, chromatin remodeling)."
  },
  {
    "q": "22 years old female with complaints of butterfly rash over the face, joint pains and photosensitivity. What is your diagnosis and mention about other clinical features? Write in detail about lab diagnosis and morphological changes in various organs.",
    "a": "Dx: Systemic Lupus Erythematosus (SLE). Other clinical features (multi-system): Constitutional (fever, fatigue, weight loss), Skin (photosensitive malar rash, discoid rash, Raynaud's, oral ulcers, alopecia), Musculoskeletal (non-erosive arthritis/arthralgia - Jaccoud's arthropathy), Renal (lupus nephritis - most prognostically significant), Cardiac (Libman-Sacks endocarditis - sterile verrucae on both surfaces of valve leaflets; pericarditis; myocarditis), Pulmonary (pleuritis, pneumonitis, ARDS, pulmonary HTN), Neuropsychiatric (lupus cerebritis, psychosis, seizures), Hematologic (hemolytic anemia, leukopenia, lymphopenia, thrombocytopenia), Serosal (pleuritis, pericarditis, peritonitis). Lab diagnosis: ANA (sensitive screening, >95%+), Anti-dsDNA (specific, correlates with disease activity, ↓ complement), Anti-Sm (most specific, 25%), Anti-Ro/SS-A (neonatal lupus, SCLE), Anti-La/SS-B, Antiphospholipid antibodies (APS), C3/C4 (decreased in active disease), CBC (cytopenias), Direct Coombs test, Urinalysis (proteinuria, hematuria, casts), Renal biopsy (WHO class I-VI nephritis). Morphology: Kidney (wire loop lesions - class IV diffuse proliferative - worst; thickened GBM by immune complexes), Spleen (onion-skin lesion of perivascular fibrosis around central arteries - pathognomonic), Skin (vacuolar degeneration of BMZ, immunofluorescence - 'lupus band' of Ig + complement at DEJ), Joints (synovitis, no erosion), Heart (Libman-Sacks endocarditis)."
  },
  {
    "q": "8-year-old boy presented with hemarthroses following a trivial injury. H/o easy bruising present. What is the clinical condition and what is the mode of inheritance? Explain the pathogenesis and laboratory findings.",
    "a": "Dx: Hemophilia A (Factor VIII deficiency) - most likely. Mode of inheritance: X-linked recessive (males affected, females carriers). Gene: F8 gene on Xq28 (Hemophilia A); F9 gene on Xq27 (Hemophilia B/Christmas disease). Pathogenesis: Deficiency of Factor VIII (Hemophilia A) or IX (Hemophilia B) → defective intrinsic pathway of coagulation → impaired Factor X activation → deficient thrombin generation → inadequate fibrin clot formation → prolonged/excessive bleeding into joints (hemarthroses), muscles, soft tissues. Severity: Severe (<1% factor activity - spontaneous bleeding), Moderate (1-5% - bleeding with minor trauma), Mild (5-40% - bleeding with major trauma/surgery). Chronic hemarthroses → synovitis → cartilage destruction → joint deformity. Lab: APTT prolonged, PT normal (extrinsic pathway intact), BT normal (platelet function intact), Factor VIII assay decreased (HA) or Factor IX assay decreased (HB), vWF antigen and activity normal (distinguishes from VWD), Inhibitor assay (check for inhibitors after multiple transfusions - mixing study). Treatment: Factor VIII/IX concentrate, DDAVP (mild HA), Emicizumab (bispecific antibody)."
  },
  {
    "q": "Write in detail about Klinefelter Syndrome and genetic abnormality associated with it.",
    "a": "Klinefelter syndrome (47,XXY): Most common sex chromosome disorder in males (1:500-1000 male births). Genetic abnormality: 47,XXY (80%), variants: 48,XXXY; 48,XXYY; 49,XXXXY; mosaics (46,XY/47,XXY - milder). Mechanism: Maternal nondisjunction in Meiosis I (most common, ~60%) or Meiosis II → extra X; or paternal nondisjunction. Extra X → one X inactivated (Barr body present) but SOME genes escape inactivation (PAR1/PAR2 regions, KAL1, SHOX genes - explains tall stature). Clinical features: Pre-pubertal diagnosis rare (tall for age, small testes). Post-pubertal: Small firm testes (hyalinized/fibrosed seminiferous tubules → azoospermia → infertility), Gynecomastia (↑ breast cancer risk 20×), Tall stature (long legs, eunuchoid body habitus), Sparse body/facial hair, Female fat distribution, Decreased libido, Osteoporosis, Mild cognitive/learning difficulty, Language processing delay. Hormonal: ↓ Testosterone, ↑ FSH (markedly), ↑ LH (both elevated due to primary gonadal failure). Diagnosis: Karyotype, Buccal smear (Barr body), Semen analysis (azoospermia), Hormonal profile. Treatment: Testosterone replacement, ART (TESE-ICSI for fertility)."
  },
  {
    "q": "Write about the pathogenesis of Amyloid.",
    "a": "Pathogenesis of Amyloid deposition: Amyloid = misfolded proteins with cross-beta-pleated sheet configuration. Step 1 - Protein overproduction/abnormal protein: AL (excess immunoglobulin light chains), AA (overproduction of SAA - acute phase reactant), ATTR (mutant/wild-type transthyretin - unstable, prone to misfolding). Step 2 - Misfolding: Native proteins partially unfold → expose hydrophobic regions → aggregate as oligomers (initial toxic species → cellular dysfunction). Step 3 - Fibril formation: Oligomers → protofilaments → fibrils (7.5-10 nm diameter, non-branching). Step 4 - Extracellular deposition: Serum amyloid P component (SAP) - binds fibrils, protects from degradation; Proteoglycans (heparan sulfate) - scaffold; ApoE - promotes deposition. Step 5 - Organ dysfunction: Direct compression, disruption of organ architecture, RAGE receptor signaling (inflammatory response). Degradation mechanisms: Macrophage phagocytosis (limited), Proteasome, Autophagy (all insufficient in disease state). Congo red stain + polarized light (apple-green birefringence) = gold standard morphologic diagnosis."
  },
  {
    "q": "Define hyperplasia and describe with two examples.",
    "a": "Hyperplasia: Increase in number of cells in an organ or tissue, usually resulting in increased volume of the organ/tissue. Cells are normal (differentiated), capable of further division. Stimulus-responsive (reversible when stimulus removed). Types: Physiological (normal response): Hormonal (breast during puberty, pregnancy; endometrium in menstrual cycle) or Compensatory (liver regeneration after partial hepatectomy, contralateral kidney hypertrophy/hyperplasia). Pathological (abnormal stimulus): Endometrial hyperplasia (excess estrogen → atypical hyperplasia → risk of adenocarcinoma), BPH (benign prostatic hyperplasia - DHT mediated), Psoriasis (epidermal hyperplasia), Thyroid (iodine deficiency goiter). Example 1 - Endometrial hyperplasia: Excess estrogen (anovulatory cycles, PCOS, obesity, exogenous estrogen without progesterone) → endometrial gland and stromal proliferation. Types: Simple, Complex, with/without atypia. Risk of malignancy: Simple without atypia (1%), Complex with atypia (25-30%). Example 2 - BPH: Periurethral transitional zone, DHT (5α-reductase converts testosterone), glandular + stromal hyperplasia → urinary obstruction symptoms."
  },
  {
    "q": "Write about ESR and its significance.",
    "a": "ESR (Erythrocyte Sedimentation Rate): Rate at which RBCs sediment in 1 hour (mm/hr). Methods: Westergren (gold standard, anticoagulated blood in 200mm tube, reading at 1 hr) - normal: Males <15 mm/hr, Females <20 mm/hr (adjusted for age: Westergren formula). Wintrobe method (shorter tube, 100mm, no dilution). Mechanism: Normal RBCs repel each other (negative surface charge - zeta potential). Increased plasma proteins (fibrinogen, globulins, acute phase reactants) → neutralize surface charge → rouleaux formation → faster sedimentation. Causes of elevated ESR: Infections (bacterial > viral), Inflammatory conditions (RA, SLE, IBD), Malignancy (especially multiple myeloma - highest ESR), Anemia, Pregnancy, Tissue necrosis, Temporal arteritis/PMR (extremely elevated >100mm/hr). False low ESR: Polycythemia, Sickle cell disease, Spherocytosis, Microcytosis, Hypofibrinogenemia. Significance: Non-specific inflammatory marker, Monitor disease activity (RA, TB, temporal arteritis), Unexplained fever workup, Screening for myeloma. Limitation: Non-specific; CRP is faster/more specific acute phase marker."
  },
  {
    "q": "List five tumour markers with their significance.",
    "a": "Tumor markers (5 important): 1) AFP (Alpha-fetoprotein): HCC (>400 ng/mL highly suggestive), Non-seminomatous germ cell tumors (testicular - yolk sac component), Physiologic in pregnancy (fetal production). 2) PSA (Prostate Specific Antigen): Prostate carcinoma screening (>4 ng/mL suspicious, >10 ng/mL high risk), Monitor treatment response and recurrence. 3) CEA (Carcinoembryonic Antigen): Colorectal carcinoma (monitoring recurrence, not screening; also elevated in lung, pancreas, breast, gastric Ca, smokers). 4) CA-125: Ovarian carcinoma (monitoring response/recurrence; not reliable for screening; also elevated in endometriosis, fibroids, PID). 5) CA 19-9: Pancreatic carcinoma (most sensitive for pancreatic Ca), Cholangiocarcinoma, Gastric Ca; Lewis antigen-dependent (may be absent in Lewis antigen-negative individuals). Others worth knowing: hCG (choriocarcinoma, gestational trophoblastic disease, testicular germ cell tumors), LDH (lymphoma, seminoma, prognosis), Calcitonin (medullary thyroid carcinoma), Chromogranin A (neuroendocrine tumors/carcinoid)."
  },
  {
    "q": "Write about Pathologic calcification.",
    "a": "Pathologic calcification: Abnormal deposition of calcium salts in tissues. Types: 1) Dystrophic calcification: Calcium deposits in dead or damaged tissue; normal serum calcium & phosphate. Mechanism: Cell death → membrane damage → mitochondrial calcium sequestration → alkaline phosphatase → hydroxyapatite crystal nucleation. Sites: Atherosclerotic plaques, Old TB foci (Ghon complex - eggshell calcification), Aging/dead heart valves (Monckeberg's medial calcification - pipestem arteries), Old thrombi, Psammoma bodies (papillary thyroid carcinoma, serous papillary ovarian Ca, meningioma, mesothelioma - concentric laminar calcification), Necrotic fat (saponification). Diagnosis: von Kossa stain (black). 2) Metastatic calcification: Calcium deposits in normal/viable tissue due to hypercalcemia. Causes: Hyperparathyroidism (most common), Hypervitaminosis D, Sarcoidosis, Milk-alkali syndrome, Multiple myeloma (bone destruction), Paget's disease. Sites: Kidney (nephrocalcinosis), Lung, Gastric mucosa (acid-secreting areas - 'Band keratopathy' in cornea). Hallmark: Predilection for tissues that excrete acid (pH gradient promotes precipitation)."
  },
  {
    "q": "Write about Warburg effect.",
    "a": "Warburg effect (Aerobic glycolysis): Phenomenon first described by Otto Warburg (1924). Normal cells: Glucose → glycolysis → pyruvate → TCA cycle + oxidative phosphorylation (OXPHOS) in mitochondria → 36-38 ATP. In hypoxia: Glucose → lactate (anaerobic glycolysis - 2 ATP). Warburg effect: Cancer cells preferentially use glycolysis even in the PRESENCE of adequate oxygen (aerobic glycolysis) → produces lactate (Warburg effect). Mechanism: Upregulation of glucose transporters (GLUT1, GLUT3), hexokinase, PFK, pyruvate kinase M2 (PKM2). Drivers: HIF-1α (hypoxia-inducible factor, also activated by RAS, PI3K), c-MYC, mutant TP53, PI3K/AKT/mTOR pathway. Why? Provides: Rapid ATP production, biosynthetic intermediates (pentose phosphate pathway → nucleotides, NADPH; acetyl-CoA for lipids; amino acid precursors) for rapidly proliferating cells, Acidic microenvironment (inhibits immune cells, promotes invasion), Mitochondrial avoidance (less ROS production). Clinical applications: PET scan uses 18F-FDG (glucose analog) → high uptake in cancer cells (FDG-avid tumors), Therapeutic target (DCA, metformin, 2-DG)."
  },
  {
    "q": "Write in detail about Phagocytosis.",
    "a": "Phagocytosis: Process by which specialized cells (neutrophils, macrophages, dendritic cells - professional phagocytes) engulf and destroy microorganisms, dead cells, and foreign particles. Steps: 1) Recognition & Attachment: Direct (pattern recognition receptors - TLRs, lectins, scavenger receptors) or opsonin-mediated (enhanced): IgG (Fc gamma receptor - FcγR) + C3b (complement receptor CR1/CR3 - C3b generated by complement activation). 2) Engulfment: Pseudopod extension around particle → zipper mechanism (sequential receptor engagement) → phagosome formation. 3) Phagolysosome formation: Phagosome fuses with lysosome → low pH (4.5-5.0), lysosomal enzymes (cathepsins, acid hydrolases, myeloperoxidase). 4) Killing: Oxygen-dependent: NADPH oxidase (phox complex) → superoxide (O2⁻) → H2O2 → MPO + Cl⁻ → HOCl (hypochlorous acid - most potent killing). Nitric oxide (iNOS). Oxygen-independent: Lysozyme, lactoferrin, defensins, elastase, BPI (bactericidal permeability-increasing protein), cathepsin G. Defects: CGD (NADPH oxidase defect - susceptible to catalase+ organisms), Chediak-Higashi (lysosomal trafficking defect - giant granules, impaired killing)."
  },
  {
    "q": "Classify AML.",
    "a": "AML Classification (WHO 2016/2022): 1) AML with recurrent genetic abnormalities (≥20% blasts or specific genetics): t(8;21)(q22;q22.1) RUNX1-RUNX1T1 (good prognosis), inv(16)(p13.1q22)/t(16;16) CBFB-MYH11 (good prognosis), t(15;17)(q22;q12) PML-RARα = APL/AML-M3 (ATRA responsive), t(9;11) MLLT3-KMT2A (intermediate), t(6;9) DEK-NUP214 (poor), t(1;22) RBM15-MKL1 (AML-M7 megakaryoblastic), inv(3)/t(3;3) GATA2-MECOM (poor), BCR-ABL1, NPM1 mutation (good if FLT3-ITD negative), biallelic CEBPA mutation (good), FLT3-ITD (poor). 2) AML with myelodysplasia-related changes. 3) Therapy-related AML/MDS (alkylating agents: del 5q/7q; topoisomerase II inhibitors: 11q23 MLL rearrangements). 4) AML, NOS (FAB subtypes): M0 (undifferentiated), M1 (minimal differentiation), M2 (with maturation - most common AML, t(8;21)), M3 (APL - Auer rods, DIC risk), M4 (myelomonocytic), M4Eo (eosinophilic), M5 (monocytic), M6 (erythroid), M7 (megakaryoblastic). Diagnosis requires: ≥20% myeloid blasts in BM/blood (except APL and CBF-AML where any % qualifies if genetic lesion present)."
  },
  {
    "q": "A 17 years old female with complaints of a mobile lump in the right breast, noticed 2 months back, has come to the cytology laboratory for FNAC of the breast lump. USG of breast shows a well circumscribed mass measuring 3x2x2 cm. How will you proceed with the patient?",
    "a": "Approach to FNAC of breast lump: Pre-procedure: Clinical history (age, lump duration, changes, family history, menstrual history), Informed consent, Explain procedure (minimally invasive, OPD basis, no stitches). USG correlation (well-circumscribed in 17F - likely Fibroadenoma). FNAC Procedure: Position - supine, arm abducted. Palpate lump, fix with non-dominant hand. Skin preparation (spirit swab). 23-24G needle with 10-20mL syringe. Insert into lump, apply negative pressure, multiple passes in different directions, release suction before withdrawing. Smear on glass slides, fix (wet fix - 95% alcohol for PAP; air dry for MGG/Giemsa). Cytological interpretation: Fibroadenoma - biphasic (epithelial + stromal) - stag horn/staghorn branching epithelial sheets, bare bipolar nuclei (stromal), myxoid stroma. Report (Thy/B system or ICR system): B1 (inadequate), B2 (benign), B3 (uncertain malignant potential), B4 (suspicious), B5 (malignant). Patient counseling: Results in 24-48 hrs. If B2 (fibroadenoma) - reassure, observation, surgical excision optional. Differential in young female: Fibroadenoma (most likely), Phyllodes, Juvenile hypertrophy."
  },
  {
    "q": "Define Thrombosis. Describe the various etiological factors for Thrombosis. Describe the morphology of Thrombus.",
    "a": "Thrombosis: Formation of a solid mass from blood constituents (platelets, fibrin, RBCs, leukocytes) within the living cardiovascular system. Etiological factors - Virchow's Triad: 1) Endothelial injury (dominant in arterial thrombosis): Atherosclerosis, Hypertension, Vasculitis, Mechanical trauma, Radiation, Chemical injury, Hyperhomocysteinemia → exposed collagen + TF + vWF → platelet adhesion + coagulation activation. 2) Abnormal blood flow (stasis in veins, turbulence in arteries): Stasis (DVT, AF, post-MI mural thrombus, immobility) → prevents dilution of activated factors, prevents inhibitor access, promotes endothelial hypoxia. Turbulence (atherosclerotic plaques, aneurysms) → endothelial injury + platelet activation. 3) Hypercoagulability (thrombophilia): Primary (genetic) - Factor V Leiden (APC resistance - most common hereditary thrombophilia), Prothrombin G20210A mutation, Antithrombin III deficiency, Protein C/S deficiency; Secondary (acquired) - Antiphospholipid syndrome, Malignancy (Trousseau's syndrome - migratory thrombophlebitis), OCP, Pregnancy, Immobilization, DIC, HIT. Morphology: Lines of Zahn (alternating pale platelet-fibrin and dark RBC-rich lines - only in antemortem thrombus, distinguishes from postmortem clot). Types: Red (venous, RBC-rich, propagating tail), White (arterial, platelet-fibrin, pale, firm), Mixed (most common). Postmortem clot: 'chicken fat' (yellow, gelatinous, no lines of Zahn) + 'currant jelly' (red, RBC-rich). Fate of thrombus: Propagation, Dissolution (fibrinolysis), Organization (granulation tissue → fibrosis), Recanalization, Embolization."
  },
  {
    "q": "65/F presenting with severe paresthesia of lower limbs, atrophic glossitis and anemia. On examination low serum vitamin B12 seen. What is the diagnosis? Discuss the etiopathogenesis, peripheral blood smear and bone marrow picture for the above diagnosis.",
    "a": "Dx: Pernicious Anemia (Vit B12 deficiency - autoimmune gastritis). Etiopathogenesis: Autoimmune destruction of gastric parietal cells → Loss of Intrinsic Factor (IF) + achlorhydria → defective Vit B12 absorption (B12 requires IF for absorption in terminal ileum). Autoantibodies: Anti-parietal cell antibodies (90%, less specific), Anti-IF antibodies (Type I - blocking Ab prevents B12-IF complex; Type II - binding Ab prevents complex absorption; more specific). B12 deficiency → impaired DNA synthesis (thymidine synthesis via methyltetrahydrofolate pathway) → megaloblastic changes in all dividing cells. Also: methionine deficiency → defective myelin synthesis → subacute combined degeneration of spinal cord (posterior + lateral columns → paresthesia, ataxia, dementia). Other causes of B12 deficiency: Dietary (strict vegans), Terminal ileum disease (Crohn's), Post-gastrectomy, Fish tapeworm (D. latum), SIBO. Peripheral blood smear: Macro-ovalocytes (pathognomonic), Hypersegmented neutrophils (≥5 lobes, >5% cells or any with ≥6 lobes - earliest finding), Anispoikilocytosis, Leukopenia, Thrombocytopenia, MCV >100 fL (sometimes >130-140 fL). Bone marrow picture: Hypercellular, Erythroid hyperplasia, Megaloblasts (open, lacy chromatin nucleus; mature cytoplasm = nuclear-cytoplasmic asynchrony), Giant bands and metamyelocytes (myeloid megaloblastic change), Hypersegmented megakaryocytes. Biochemistry: Elevated LDH, elevated unconjugated bilirubin (ineffective erythropoiesis - intramedullary hemolysis)."
  },
  {
    "q": "Write about Type I Hypersensitivity reaction.",
    "a": "Type I = Immediate/Anaphylactic hypersensitivity (IgE-mediated). Two phases: Sensitization: First exposure to allergen (antigen) → APC presents to Th2 cells → IL-4, IL-13 (class switching B cells) → IgE production → IgE binds FcεRI receptors on mast cells/basophils (no reaction yet). Elicitation (seconds to minutes): Re-exposure → antigen crosslinks adjacent IgE molecules on mast cells → mast cell degranulation → PRIMARY MEDIATORS: Histamine (vasodilation, increased permeability, bronchoconstriction, increased secretions), Heparin (anticoagulant), ECF-A (eosinophil chemotaxis), NCF-A (neutrophil chemotaxis), Tryptase (diagnostic marker). Late phase (2-24 hrs) - SECONDARY MEDIATORS (newly synthesized): PGD2 (bronchoconstriction, vasodilation), LTC4, LTD4, LTE4 (SRS-A - slow reacting substance - sustained bronchoconstriction, mucus secretion), LTB4 (neutrophil chemotaxis), PAF, IL-5 (eosinophil activation). Clinical: Local (allergic rhinitis, urticaria, food allergy, eczema) → Systemic anaphylaxis (laryngeal edema, bronchospasm, vascular collapse → death if untreated). Examples: Allergic asthma, Bee sting anaphylaxis, Penicillin allergy, Food allergy (peanut). Diagnosis: Skin prick test, RAST (serum specific IgE). Treatment: Epinephrine (anaphylaxis), Antihistamines, Corticosteroids, Desensitization."
  },
  {
    "q": "Write about Antiphospholipid Antibody Syndrome (APS).",
    "a": "APS: Autoimmune acquired thrombophilia. Diagnostic criteria (Sapporo/Revised Sapporo): Clinical (vascular thrombosis - arterial/venous/small vessel; pregnancy morbidity - ≥3 early miscarriages, fetal loss, severe preeclampsia) + Lab (positive on ≥2 occasions, ≥12 weeks apart): Lupus anticoagulant (LA), Anti-cardiolipin antibodies (aCL - IgG/IgM), Anti-β2-glycoprotein I antibodies (aβ2GPI - IgG/IgM). Pathogenesis: Antibodies target β2-GPI (natural anticoagulant) on phospholipid surfaces → paradoxical procoagulant state: Inhibit protein C/S, Inhibit antithrombin, Activate endothelial cells (TF expression), Activate platelets, Inhibit annexin V (placental anticoagulant). Primary APS vs Secondary (SLE, RA, drugs). Paradox: Lupus anticoagulant prolongs APTT in vitro (mixing study does not correct) but THROMBOTIC in vivo. Lab: Prolonged APTT (not corrected by mixing), Kaolin clotting time, DRVVT (dilute Russell viper venom time - most specific for LA), Anti-cardiolipin ELISA, Anti-β2GPI ELISA. Catastrophic APS (CAPS): Thrombosis in ≥3 organs simultaneously → MODS, very high mortality. Treatment: Anticoagulation (heparin → warfarin long-term for thrombosis), Low-dose aspirin + LMWH in pregnancy."
  },
  {
    "q": "Write about Fracture healing.",
    "a": "Fracture healing (Bone repair): Similar to soft tissue healing but involves specialized bone repair. Phases: 1) Hematoma formation (days 1-3): Fracture → vessel rupture → hematoma → fibrin clot → scaffold for repair. 2) Soft callus/Procallus formation (days 3-14): Periosteal & endosteal cells, MSCs recruited → chondroblasts → fibrocartilaginous callus (type II collagen + chondrocytes + woven bone peripherally). 3) Hard callus/Bony callus (weeks 3-12): Enchondral ossification → replace cartilage with woven bone → bony bridging of fracture gap. 4) Remodeling (months-years): Woven bone → lamellar bone (osteoclast resorption + osteoblast replacement), restoration of medullary cavity, original bone shape and strength. Growth factors: PDGF, TGF-β, BMPs (bone morphogenetic proteins - key for osteogenesis), VEGF, FGF, IGF. Factors affecting healing: Good (adequate immobilization, good blood supply, young age, proper nutrition, normal bone density). Bad (infection, poor immobilization, large gap, avascular necrosis, osteoporosis, steroids, diabetes, malnutrition, pathological fracture through tumor). Complications: Non-union, Malunion, Delayed union, Avascular necrosis (femoral head, scaphoid), Myositis ossificans."
  },
  {
    "q": "Write about Sideroblastic Anemia.",
    "a": "Sideroblastic anemia: Group of anemias characterized by ringed sideroblasts in bone marrow (erythroblasts with iron-laden mitochondria arranged in ring around nucleus - Prussian blue stain). Pathogenesis: Defective heme synthesis (delta-aminolevulinic acid synthase 2 - ALAS2 or other heme pathway enzymes) → iron cannot be incorporated into heme → iron accumulates in mitochondria → ringed sideroblasts → ineffective erythropoiesis + iron overload. Causes: Congenital: X-linked (ALAS2 mutation - males affected), Autosomal recessive, Mitochondrial. Acquired: Alcohol (most common - B6 antagonist, direct mitochondrial toxin), Isoniazid, chloramphenicol, lead (inhibits ALAD), Copper deficiency, Zinc excess, Idiopathic (MDS-RS - myelodysplastic syndrome with ring sideroblasts - SF3B1 mutation in most). Lab: Microcytic hypochromic anemia (inherited) or dimorphic blood picture (MDS), Elevated serum iron + ferritin + transferrin saturation (iron overload), Low TIBC, Basophilic stippling (lead poisoning), Bone marrow: ringed sideroblasts (≥15% of erythroblasts), Erythroid hyperplasia. Treatment: Pyridoxine (B6) for X-linked/INH-induced, Remove cause (alcohol, drugs), Transfusion, Desferrioxamine (iron overload), Lenalidomide/ESA for MDS-RS."
  },
  {
    "q": "Write about Tumor metastasis.",
    "a": "Tumor metastasis: Spread of cancer cells from primary tumor to distant sites. Hallmark of malignancy (not seen in benign tumors). Routes: 1) Lymphatic (carcinomas - most common) - regional lymph nodes → sentinel node concept. 2) Hematogenous (sarcomas + carcinomas) - arteries resist (wall), veins common (liver via portal, lung via systemic veins, bone - Batson's plexus). 3) Transcoelomic/Seeding - ovarian Ca (peritoneal spread, Krukenberg tumor = metastatic signet ring cell carcinoma to ovary, usually from gastric primary), pleura. 4) Perineural - prostate, pancreatic, head/neck Ca. 5) Iatrogenic (surgical seeding, biopsy tract). Metastatic cascade (steps): Detachment from primary (E-cadherin loss, EMT), Invasion of ECM (MMP-2, MMP-9, type IV collagenase), Intravasation, Survival in circulation, Arrest at distant site, Extravasation, Colonization (pre-metastatic niche, VEGF, LOX, BMDCs). Organ tropism: 'Seed and soil' (Paget): Breast → bone, lung, liver, brain; Prostate → bone (osteoblastic); Colon → liver (portal); Lung → adrenal, brain. Epithelial-mesenchymal transition (EMT): Snail, Slug, Twist, ZEB transcription factors → loss of E-cadherin → gain of N-cadherin, vimentin → mesenchymal phenotype → motile, invasive."
  },
  {
    "q": "Write about Graft versus Host disease (GvHD).",
    "a": "GvHD: Complication of allogeneic hematopoietic stem cell transplantation (HSCT) where donor T lymphocytes recognize host tissues as foreign and mount immune response against recipient. Prerequisite: Donor must contain immunologically competent cells (T cells), Recipient must be immunocompromised (cannot reject graft), Antigenic difference between donor and host (MHC mismatch). Acute GvHD (within 100 days): Donor T cells recognize host alloantigen (HLA mismatch) → alloreactive Th1 CD4+ + CTL CD8+ → target organs: skin (maculopapular rash → desquamation), GI (watery/bloody diarrhea, vomiting, abdominal pain → mucosal ulceration), Liver (jaundice, elevated LFT - biliary epithelium damage). Chronic GvHD (>100 days): More complex; resembles autoimmune disease. Skin (scleroderma-like fibrosis), Dry eyes/mouth (sicca syndrome), Liver (chronic hepatitis, cirrhosis), Lung (bronchiolitis obliterans). Pathogenesis: Phase 1 - conditioning regimen → tissue damage → cytokines (TNF, IL-1); Phase 2 - donor T cell activation (direct alloreactivity or indirect); Phase 3 - effector phase (CTL + Th1 cytokines → organ damage). GvL (Graft-versus-Leukemia): Beneficial effect - donor immune cells kill residual leukemia cells - reduces relapse. Separation of GvHD and GvL is a therapeutic goal. Prevention: HLA matching, T cell depletion, immunosuppression (cyclosporin, tacrolimus, MTX, steroids)."
  },
  {
    "q": "Write about Down's Syndrome.",
    "a": "Down syndrome (Trisomy 21): Most common chromosomal abnormality (1:700 live births). Genetics: Trisomy 21 (95%) - meiotic nondisjunction (95% maternal, usually meiosis I; risk ↑ with maternal age); Robertsonian translocation (4%) - 46 chromosomes but extra chr 21 material attached to chr 14 (familial, no maternal age effect, recurrence risk higher); Mosaicism (1%) - milder features. Mechanism of nondisjunction: Failure of homologous chromosome separation in meiosis I or II → ovum with 2 copies of chr 21 → trisomy 21 after fertilization. Clinical features: Intellectual disability (mild-moderate, IQ 25-75), Hypotonia, Flat facies, Small ears (dysplastic), Upward slanting palpebral fissures, Epicanthal folds, Brushfield spots (speckled iris), Protruding tongue, Single palmar crease (simian crease), Wide gap between 1st and 2nd toe (sandal gap), Short stature. Associated conditions: Congenital heart disease (40-50%, AVSD/VSD most common), Duodenal atresia ('double bubble'), Hirschsprung's disease, Leukemia (ALL 10-20× risk, AML-M7 in neonates), Alzheimer's disease (>40 yrs - APP gene on chr 21), Hypothyroidism, Celiac disease, Atlantoaxial instability. Diagnosis: Prenatal (triple/quad screen - AFP, hCG, estriol, inhibin A; NIPT; amniocentesis/CVS for karyotype), Postnatal karyotype."
  },
  {
    "q": "Write about Pathogenesis of Acquired Immunodeficiency syndrome (AIDS).",
    "a": "AIDS pathogenesis: HIV (Human Immunodeficiency Virus) - Lentivirus, ssRNA retrovirus, 2 types: HIV-1 (pandemic), HIV-2 (West Africa, less virulent). Structure: gp120+gp41 (envelope), p24 (capsid), RT, Integrase, Protease. Transmission: Sexual (commonest), Blood/blood products, Vertical (mother-to-child). Pathogenesis: Entry: gp120 binds CD4 (primary receptor) + CCR5 (early) or CXCR4 (late) co-receptor → gp41 fusion peptide → membrane fusion → viral RNA enters cell. Replication: RT → proviral DNA → integrase → integration into host genome (latent reservoir). Activation → viral replication → new virions → cell death. Mechanisms of CD4 depletion: Direct cytopathic (viral replication → cell lysis), Apoptosis (gp120 crosslinks CD4 → FasL/Fas), CD8 CTL killing of infected CD4 cells, Syncytium formation (multinucleated giant cells), Impaired production, Immune activation-induced apoptosis. Immunological course: Acute HIV syndrome (3-6 wks) - mononucleosis-like, high viremia. Latent phase (years, ~10 yrs untreated) - low viremia, gradual CD4 decline. AIDS (CD4 <200 cells/μL) - OIs, AIDS-defining malignancies (Kaposi's, CNS lymphoma, invasive cervical Ca). Viral load set point after acute infection predicts progression rate. HAART (Highly Active Antiretroviral Therapy): NRTIs, NNRTIs, PIs, Integrase inhibitors, CCR5 antagonists."
  },
  {
    "q": "Write about Asbestosis.",
    "a": "Asbestosis: Pulmonary fibrosis caused by inhalation of asbestos fibers (amphibole type - crocidolite, amosite - more dangerous than serpentine/chrysotile due to rigidity and persistence). Occupations at risk: Mining, shipbuilding, insulation, construction (brake pads). Pathogenesis: Asbestos fibers inhaled → deposited in bifurcations of respiratory bronchioles → macrophage phagocytosis (incomplete - frustrated phagocytosis) → NLRP3 inflammasome activation → IL-1β, IL-18 → macrophage activation → TGF-β, PDGF, IL-8 → fibroblast activation → collagen deposition → interstitial fibrosis. Morphology: Diffuse interstitial fibrosis (lower lobes, subpleural) → honeycomb lung (end stage). Asbestos bodies (ferruginous bodies): Dumbbell-shaped (asbestos fiber coated with hemosiderin + protein) - Prussian blue positive, pathognomonic. Pleural plaques (hallmark of asbestos exposure but NOT asbestosis): Hyalinized fibrous plaques on parietal pleura, diaphragm (calcified). Asbestos-related diseases: Asbestosis, Pleural plaques, Pleural effusion (earliest manifestation), Mesothelioma (malignant - pleura/peritoneum, long latency 25-40 yrs; associated with crocidolite; calretinin+ on IHC), Lung cancer (synergistic with smoking - 50× risk for smokers exposed to asbestos). Diagnosis: HRCT chest, BAL (asbestos bodies), PFT (restrictive pattern)."
  },
  {
    "q": "How will you counsel the patient with IBD (Inflammatory Bowel Disease)?",
    "a": "IBD counseling approach: Establish rapport, confirm understanding of diagnosis (Crohn's disease vs Ulcerative Colitis). Explain disease: IBD = chronic immune-mediated condition (not patient's fault), no definitive cure but manageable, Lifelong condition with remissions and flares. Differentiate from IBS (patients often confuse). Address specific concerns: Diet (no single diet cures IBD; nutritional deficiencies common - iron, B12, folate, Vit D, calcium; keep food diary; avoid trigger foods during flare). Medications (immunosuppressants - risk vs benefit, adherence crucial, do not stop without consultation). Surgery (may be needed, colectomy cures UC, Crohn's recurs). Colorectal cancer risk (long-standing pancolitis → regular surveillance colonoscopy). Pregnancy (disease control pre-pregnancy, some medications safe, discuss with gastroenterologist). Mental health (depression/anxiety common, refer to counselor/support groups). Lifestyle: Stress management, adequate sleep, smoking cessation (UC - smoking has protective effect but Crohn's - smoking worsens; counsel accordingly - patient still should not smoke). AETCOM principle: Patient autonomy, empathy, shared decision-making, non-abandonment."
  },
  {
    "q": "Define Neoplasia. Describe the pathogenesis of Radiation oncogenesis. What are the characteristics of Benign and Malignant Neoplasms.",
    "a": "Neoplasia (Willis definition): 'Abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the change.' Radiation oncogenesis pathogenesis: Ionizing radiation (X-rays, gamma rays, nuclear) → DNA double-strand breaks → misrepair → point mutations, chromosomal breaks, translocations → oncogene activation (RAS) + tumor suppressor inactivation (TP53, RB). Key: Dose-dependent, no threshold, cumulative. Examples: Post-Chernobyl thyroid Ca (papillary thyroid Ca - RET/PTC rearrangement), Post-radiation sarcomas, Leukemia (AML/CML - A-bomb survivors, peak 5-7 yrs), Breast Ca. UV radiation: Non-ionizing → DNA thymine dimers (pyrimidine dimers) → defective NER (Xeroderma Pigmentosum) → skin cancers (BCC, SCC, melanoma). Characteristics - Benign vs Malignant: BENIGN: Well-differentiated, resembles parent tissue; Slow growth; No metastasis; Pushing/expansile (not infiltrative) borders; Regular capsule (fibrous); Low mitotic rate (no atypical mitoses); No necrosis usually. MALIGNANT: Poorly/undifferentiated (anaplastic in extreme); Rapid growth; Metastasis (hallmark); Invasive margins (irregular borders); No capsule (irregular); High mitotic rate + ATYPICAL mitoses; Necrosis common; Nuclear pleomorphism, hyperchromasia, prominent nucleoli; High N:C ratio."
  },
  {
    "q": "5-year-old boy presents to ER with complaints of epistaxis and petechiae over the limbs for the past 3 days. What is the probable condition? What are the relevant investigations to narrow down the cause? Write in detail about pathogenesis of immune mediated cases of the above condition.",
    "a": "Probable condition: Thrombocytopenic Purpura (ITP vs other causes - TTP, HUS, DIC, aplastic anemia, leukemia). Investigations to narrow down cause: 1st line: CBC (platelets count, Hb, TLC - isolated thrombocytopenia vs pancytopenia), Peripheral smear (platelet morphology, blast cells, schistocytes), PT & APTT (coagulation - normal in ITP), BT (prolonged). Additional: Bone marrow aspiration (megakaryocyte hyperplasia in ITP, aplasia in aplastic anemia, infiltration in leukemia), DRVVT/mixing studies (if coagulation problem), Anti-platelet antibodies, ANA/anti-dsDNA (SLE), HIV/HCV serology, Blood culture, H. pylori antigen, LFT, Renal function (HUS/TTP - schistocytes + thrombocytopenia + renal failure). Pathogenesis of Immune-mediated (ITP): Pre-trigger (viral infection/molecular mimicry in children - post-viral ITP) → breakdown of immune tolerance to platelet glycoproteins (GpIIb/IIIa = integrin αIIbβ3, GpIb/IX) → Autoreactive B cells (with T-cell help - Th2/Treg imbalance) → IgG autoantibodies (anti-GpIIb/IIIa most common) → Fc-mediated phagocytosis of opsonized platelets by splenic macrophages (FcγRIII) → Thrombocytopenia. Additional mechanisms: CTL (CD8+) direct platelet killing, Anti-platelet antibodies inhibit megakaryocyte maturation → impaired thrombopoiesis. Spleen: Primary site of autoantibody production + platelet destruction (splenectomy therapeutic). In children: Usually acute, self-limiting (post-viral), monophasic. Chronic ITP (adults, >12 months): Sustained autoimmune process."
  },
  {
    "q": "Write about Tumor markers.",
    "a": "Tumor markers: Molecules produced by tumor cells or normal cells in response to tumor, detectable in blood/urine/tissue. Characteristics of ideal: High sensitivity (few false negatives), High specificity (few false positives), Correlate with tumor burden, Measure treatment response, Detect recurrence early. Uses: Screening (PSA, CA-125 limited), Diagnosis (when combined with clinical features), Monitoring treatment response and remission, Detecting recurrence, Prognosis. Classification: Oncofetal antigens: AFP (HCC, germ cell tumors, normal fetal liver/yolk sac), CEA (colorectal, lung, breast, gastric, pancreatic Ca; non-specific). Hormones: hCG (gestational trophoblastic disease, testicular germ cell tumors), Calcitonin (medullary thyroid Ca), ACTH (ectopic - small cell lung Ca). Carbohydrate antigens (mucins): CA-125 (ovarian), CA 19-9 (pancreatic, biliary), CA 15-3 (breast monitoring), CA 72-4 (gastric). Enzymes: PSA (prostate), ALP (liver/bone), LDH (lymphoma, testicular), NSE (neuroendocrine/small cell lung), Acid phosphatase (prostate - superseded by PSA). Protein markers: Paraprotein/M-spike (myeloma), β2-microglobulin (myeloma/lymphoma prognosis), Chromogranin A (neuroendocrine tumors), Thyroglobulin (differentiated thyroid Ca post-thyroidectomy monitoring). Gene products: HER2/neu (breast - trastuzumab target), EGFR (NSCLC), KRAS (colorectal - anti-EGFR response predictor)."
  },
  {
    "q": "Write about Hemophilia.",
    "a": "Hemophilia: Inherited bleeding disorder due to coagulation factor deficiency. Types: Hemophilia A (Factor VIII deficiency, 80%, most common), Hemophilia B/Christmas disease (Factor IX deficiency, 15%), Hemophilia C (Factor XI deficiency, rare, mild). Genetics: X-linked recessive (A & B) - Males affected, Females carriers (1/2 daughters carriers, 1/2 sons affected). Gene: F8 (Xq28) in HA, F9 (Xq27) in HB. Mutation types: Inversion (intron 22 inversion - 45% severe HA), Deletion, Nonsense, Missense. Severity (based on factor activity): Severe (<1%) - spontaneous bleeding, hemarthroses, muscle hematomas; Moderate (1-5%) - minor trauma bleeding; Mild (5-40%) - major trauma/surgical bleeding only. Clinical: Hemarthroses (hallmark - knee, ankle, elbow → chronic synovitis → arthropathy), Muscle hematomas (compartment syndrome), Intracranial hemorrhage (most dangerous), Retroperitoneal bleeds, Post-circumcision/dental bleeding. Lab: APTT prolonged, PT normal, BT normal, Platelet count normal, Factor VIII/IX assay (specific), Mixing study (corrects = factor deficiency; does not correct = inhibitor). Complications: Inhibitor development (IgG anti-FVIII in 30% severe HA - treated with bypassing agents - rFVIIa/FEIBA), Blood-borne infections (pre-recombinant era - HIV, HCV), Joint destruction. Treatment: FVIII/IX concentrates (recombinant preferred), DDAVP (Desmopressin - mild HA, releases endogenous FVIII/vWF), Antifibrinolytics (tranexamic acid - mucosal bleeding), Emicizumab (bispecific antibody, FVIII mimetic, subcutaneous), Gene therapy (clinical trials)."
  },
  {
    "q": "Write about Dystrophic and pathologic calcification.",
    "a": "Calcification types: Dystrophic calcification: Calcium deposition in dead or damaged (necrotic, degenerating) tissue. Serum calcium and phosphate levels are NORMAL. Mechanism: Dead cells → membrane damage → Ca²⁺ influx into mitochondria → initial calcium deposits (nucleation); Acidic pH from necrosis promotes precipitation; Phospholipid breakdown → inorganic phosphate + calcium → hydroxyapatite crystal formation; Alkaline phosphatase from dying cells promotes nucleation. Sites: Atherosclerotic plaques (intimal), Caseous necrosis of TB (Ghon complex - eggshell/popcorn calcification), Heart valves (rheumatic scarring, calcific aortic stenosis), Organizing thrombi, Dead parasites (cysticercus, echinococcus), Old hematomas, Psammoma bodies (papillary thyroid Ca, serous ovarian Ca, meningioma, mesothelioma). Pathologic (Metastatic) calcification: Calcium deposition in NORMAL/viable tissues due to HYPERCALCEMIA. Causes: Hyperparathyroidism (most common cause), Hypervitaminosis D, Sarcoidosis (macrophage 1-alpha hydroxylase activity → excess calcitriol), Milk-alkali syndrome, Malignancy (myeloma, bony metastases, PTHrP production), Immobilization (bone resorption), Paget's disease. Sites predilection: Tissues that excrete acid (interstitial kidney - nephrocalcinosis, most important; gastric mucosa; lung alveolar walls; blood vessels - media; cornea - band keratopathy). Morphology: Both stain purple/blue with H&E; von Kossa stain (black); Alizarin red (orange-red). Clinical significance: Nephrocalcinosis → renal failure; Lung calcification → respiratory failure; Cardiac calcification → arrhythmia."
  },
  {
    "q": "Write about Different types of giant cells with morphology and examples.",
    "a": "Giant cells (multinucleated): Formed by fusion of macrophages. Types: 1) Langhans giant cell: Peripheral horseshoe/ring arrangement of nuclei at periphery of cell; seen in TB (granulomatous inflammation), sarcoidosis, syphilis, leprosy (tuberculoid), foreign body reaction to some materials, fungal infections. 2) Foreign body giant cell: Random/haphazard arrangement of nuclei throughout cytoplasm (central nuclei); seen in foreign body reaction (sutures, talc, silica, splinters, breast implant material). 3) Touton giant cell: Central ring of nuclei surrounded by foamy (lipid-laden) cytoplasm peripherally; seen in fat necrosis, xanthoma, juvenile xanthogranuloma, Xanthomatous lesions. 4) Osteoclast-type giant cell: Many nuclei (>20), uniform small nuclei; seen in giant cell tumor of bone (osteoclastoma), giant cell arteritis (temporal arteritis). 5) Reed-Sternberg cell: Binucleated/bilobed with prominent 'owl eye' inclusion-like nucleoli; seen in Hodgkin's lymphoma (pathognomonic). 6) Warthin-Finkeldey giant cell: Giant cells in lymphoid tissue; seen in measles (paramyxovirus). 7) Viral giant cells/syncytia: HSV, CMV, HIV, measles - multinucleated infected cells. 8) Megakaryocyte: Bone marrow; platelet production (normal). Significance: Giant cell = marker of chronic granulomatous inflammation when associated with granuloma."
  },
  {
    "q": "Write about Protein Energy Malnutrition.",
    "a": "PEM (Protein Energy Malnutrition): Spectrum of conditions from inadequate protein and/or calorie intake. WHO definitions: Wasting = low weight-for-height (acute malnutrition), Stunting = low height-for-age (chronic), Underweight = low weight-for-age. Types: Marasmus: Severe energy + protein deficiency. Features: Severe muscle wasting + subcutaneous fat loss, 'Old man' face, Grossly underweight (<60% expected), No edema, Irritable, Hair changes (less prominent), Intellect relatively spared. Serum albumin: Normal (adaptive). Kwashiorkor: Predominantly protein deficiency (relatively adequate calories from carbohydrates). Features: Edema (pitting, cardinal feature - hypoalbuminemia → osmotic pressure drop → fluid shift), 'Pot belly', 'Flaky paint' dermatosis, Hair changes (flag sign - alternating bands), 'Moon face', Hepatomegaly (fatty liver - deficient apoproteins → triglyceride accumulation), Psychomotor changes, SEVERE hypoalbuminemia. Marasmic Kwashiorkor: Features of both. Pathophysiology of edema in Kwashiorkor: Low protein intake → low serum albumin → reduced oncotic pressure → third-spacing → edema + ascites. Immunity: Reduced T-cell function (thymic atrophy), IgA deficiency → susceptibility to infections. Vitamin deficiencies commonly associated. Management: WHO F-75 then F-100 therapeutic feeds, micronutrient supplementation, treat infections, RUTF (ready-to-use therapeutic food)."
  },
  {
    "q": "Write about Glycogen storage disorders.",
    "a": "Glycogen storage disorders (GSDs): Inherited enzyme deficiencies affecting glycogen synthesis, degradation, or utilization → abnormal glycogen accumulation in various tissues. Inheritance: Mostly autosomal recessive (except Phosphoglycerate kinase def - X-linked). Classification (by enzyme and predominant tissue): Type I - Von Gierke's disease (Glucose-6-phosphatase deficiency) - Liver & Kidney - Severe hypoglycemia, massive hepatomegaly, lactic acidosis, hyperuricemia, hyperlipidemia, NO muscle involvement, Doll-like facies. Type II - Pompe's disease (Acid maltase/Acid alpha-glucosidase deficiency, GAA gene) - Lysosomal! - Heart, skeletal muscle, liver - Infantile: cardiomegaly (massive), hypotonia, respiratory failure → death <2 yrs; Adult: proximal myopathy, respiratory failure. Type III - Cori's disease (Debranching enzyme deficiency) - Liver + Muscle - Milder than Type I, hepatomegaly, muscle weakness. Type IV - Andersen's disease (Branching enzyme deficiency) - Liver - Cirrhosis, liver failure, abnormal glycogen (amylopectin-like). Type V - McArdle's disease (Muscle phosphorylase/Myophosphorylase deficiency) - Muscle ONLY - Exercise intolerance, painful cramps, myoglobinuria after vigorous exercise, NO hepatomegaly, ischemic forearm exercise test (no lactate rise but ammonia rises). Type VI - Hers disease (Liver phosphorylase) - mild hepatomegaly. Diagnosis: Enzyme assay (leukocytes/tissue), Genetic testing, Muscle/liver biopsy (PAS stain - glycogen accumulation). Treatment: Pompe - Alglucosidase alfa (ERT - enzyme replacement)."
  },
  {
    "q": "Write about Mechanism of autoimmunity.",
    "a": "Autoimmunity: Breakdown of self-tolerance leading to immune response against self-antigens. Normal tolerance mechanisms (central + peripheral): Central tolerance: Clonal deletion of self-reactive T cells in thymus (negative selection by AIRE gene products) and B cells in bone marrow. Peripheral tolerance: Anergy (T cell activation without co-stimulation → unresponsive), Regulatory T cells (Tregs - FoxP3+, IL-10, TGF-β - suppress autoreactive cells), Clonal ignorance (self-antigens sequestered/low levels - not encountered), CTLA-4 and PD-1 inhibitory signaling. Mechanisms of autoimmunity: 1) Molecular mimicry: Pathogen antigen resembles self-antigen → antibodies/T cells cross-react (e.g., Strep M protein → cardiac myosin → rheumatic fever; Campylobacter → gangliosides → Guillain-Barré). 2) Bystander activation: Infection → tissue damage → release of sequestered antigens + adjuvant effect → activation of previously ignorant autoreactive cells. 3) Epitope spreading: Initial response to foreign antigen → spread to adjacent self-epitopes. 4) Loss of Tregs: FoxP3 mutations (IPEX syndrome - polyendocrinopathy). 5) Polyclonal B cell activation: EBV, LPS → non-specific B cell activation → autoantibody production. 6) Exposure of hidden (cryptic/sequestered) antigens: Trauma → thyroglobulin release (Hashimoto's), lens protein (post-traumatic uveitis), myelin (MS). 7) Genetic factors: HLA association (HLA-DR3/DR4 in T1DM; HLA-DR2/DR3 in SLE; HLA-B27 in ankylosing spondylitis), complement deficiencies (C2/C4 in SLE)."
  },
  {
    "q": "How will you break the news of carcinoma of pancreas and explain the prognosis to the patient/attender?",
    "a": "Breaking bad news - SPIKES Protocol: S - Setting: Private room, comfortable setting, tissues available, ensure patient not alone (family member present), switch off phones, sit at same level. P - Perception: 'What have you been told so far about your condition?' - assess baseline understanding. I - Invitation: 'How much would you like to know about the results?' - assess information preference (some want all details, others prefer family first). K - Knowledge/Information: Warn shot - 'I'm afraid the results show something serious.' Use simple language (avoid jargon) - 'The tests confirm that there is a growth/cancer in the pancreas.' Allow pauses, do not rush. E - Emotions/Empathy: Allow patient to react (silence, crying, anger - do not interrupt). Acknowledge: 'This must be very difficult to hear.' Validate feelings. Avoid false reassurance but maintain realistic hope. Prognosis of pancreatic Ca: Explain gently - Pancreatic cancer has a serious prognosis; 5-year survival ~10% overall (resectable - up to 20-25%; most diagnosed at advanced stage). Emphasize: 'We will work together as a team'; Discuss available options: surgery (if operable - Whipple's procedure), chemotherapy (gemcitabine/FOLFIRINOX), palliative care, clinical trials, pain management, nutritional support, psychological support. S - Summary/Strategy: Summarize discussion, next steps, follow-up appointment, written information, helpline numbers, palliative care referral. Document discussion. AETCOM principles: Truth-telling, respect autonomy, empathy, non-abandonment."
  }
]