Answers According To Harsh Mohan's Textbook Of Pathology

Here are the answers variant-wise as requested, strictly according to Harsh Mohan's Textbook of Pathology (7th or 8th edition).

Billet 31

1. Venous Hyperemia

- Definition: Increased blood volume in veins and capillaries due to impaired outflow.

• Pathogenesis: Mechanical obstruction (e.g., thrombosis, pressure), heart failure.

- Morphology: Congested organs are cyanotic (blue-red), wet (edema), and may show chronic venous congestion changes.

• Outcomes: Edema, hypoxia, fibrosis (e.g., nutmeg liver, brown induration of lung).

2. Breast Cancer

- Definition: Malignant epithelial tumor of breast ducts/lobules.

- Classification: Non-invasive (D.C.I.S, L.C.I.S) and invasive (Invasive ductal carcinoma N.O.S – most common, 80%).

- Morphology: Hard, gritty, stellate tumor with infiltrative borders. Histology shows irregular glands, desmoplasia.

• Spread: Lymphatic (axillary nodes), hematogenous (bone, lung, liver, brain).

3. Cyanotic and Acyanotic Group of C.H.D

Refer to Chapter: Cardiovascular System Feature Acyanotic C.H.D Cyanotic C.H.D Oxygen saturation Normal Low (due to right-to-left shunt)

Examples V.S.D, A.S.D, P.D.A, Coarctation of ay-or-tuh Tetralogy of Fallot, Transposition of great arteries, Truncus arteriosus Mechanism Left-to-right shunt (acyanotic) leads to later Eisenmenger syndrome (cyanotic) Right-to-left shunt leads to deoxygenated blood enters systemic circulation Clinical Heart failure, murmur Cyanosis, clubbing, polycythemia

4. Urolithiasis, Hydronephrosis

Refer to Chapter: Urinary System

- · Urolithiasis: Formation of calculi (calcium oxalate – most common). Causes obstruction,

- infection, hematuria.

- · Hydronephrosis: Dilation of renal pelvis and calyces due to urinary obstruction (e.g., stone, stricture, B.P.H).

- · Morphology: Blunted calyces (early), thin renal parenchyma (late hydronephrosis leads to hydronephrotic atrophy).

3rd Variant

1. Regeneration and Repairing: Types of Regeneration. Pathological Regeneration.

Refer to Chapter: Inflammation & Repair

- Types of Regeneration:

- · Physiological: Continuous turnover (e.g., skin, G.I.T mucosa).

- · Reparative: After injury in labile/stable tissues (e.g., liver, kidney tubules).

• Pathological Regeneration: Abnormal proliferation leads to cirrhosis (liver), pseudoglandular hyperplasia in chronic inflammation.

- · Repair: Replacement by fibrous tissue (scar) when regeneration fails.

2. Metastasis: Ways of Metastasing. Metastatic Cascade.

- · Ways: Lymphatic (carcinomas), Hematogenous (sarcomas), Transcoelomic (peritoneal/pleural seeding).

• Metastatic Cascade:

1. Detachment & invasion (downregulate E-cadherin)

2. Intravasation

3. Circulation survival

4. Arrest & extravasation

5. Angiogenesis & proliferation at distant site

3. Anemias Due to Blood Loss: Types, Etiology, Morphology, Blood Picture, Outcomes

Refer to Chapter: Haematopoietic System Acute Blood Loss Chronic Blood Loss Etiology Trauma, ruptured aneurysm Menorrhagia, peptic ulcer, hemorrhoids Morphology Pallor, hypovolemic shock Pallor, glossitis, koilonychia Blood Picture Normocytic normochromic (initially) leads to reticulocytosis Microcytic hypochromic (iron deficiency)

Outcomes Shock, death; recovery if bleeding stops Iron deficiency anemia, fatigue

4. Tuberculosis: Etiology, Epidemiology, Pathogenesis, Classification. Structure of Tuberculous Granuloma.

Already answered in previous response – refer to T.B section above.

--- V-7

1. Primary and Secondary Amyloidosis – Morphology, Pathogenesis

Primary (A.L) Secondary (A.A)

Protein Immunoglobulin light chains S.A.A protein Associated condition Multiple myeloma, plasma cell dyscrasia Chronic inflammation (T.B, R.A, osteomyelitis)

Morphology Heart, tongue, G.I.T Kidney, liver, spleen Spleen Not characteristic "Sago" (nodular) or "Lardaceous" (diffuse)

2. Carcinogenesis – Classification and Oncogenes, Anti-oncogenes

Refer to Chapter: Neoplasia

• Classification of Carcinogens:

- · Chemical (polycyclic hydrocarbons, aromatic amines)

- · Physical (radiation, U.V)

- · Biological (viruses, bacteria, parasites)

- · Oncogenes: Mutated proto-oncogenes (promote growth) – for example, R.A.S, myc, H.E.R.2/neu.

- Anti-oncogenes (Tumor Suppressor Genes): Normally inhibit growth - for example, p53, R.B, A.P.C, B.R.C.A.1/2.

3. Disseminated Tuberculosis – Way of Dissemination

Already answered in previous response.

4. Inflammatory Bowel Disease: Crohn's Disease and Ulcerative Colitis

Already answered in previous response (comparison table).

Billet 9

1. Autoimmunity

Refer to Chapter: Immunopathology

- Definition: Immune response against self-antigens.

• Mechanisms: Loss of self-tolerance (central/peripheral), molecular mimicry, epitope spreading.

• Examples: S.L.E, R.A, Hashimoto thyroiditis, Type 1 D.M.

2. Viral Carcinogens

Refer to Chapter: Neoplasia Virus Associated Cancer

- H.P.V Cervical carcinoma, oropharyngeal

- E.B.V Burkitt lymphoma, Nasopharyngeal carcinoma

- H.B.V / H.C.V Hepatocellular carcinoma

- H.T.L.V-1 Adult T-cell leukemia/lymphoma

- H.H.V-8 Kaposi sarcoma

3. Primary Tuberculosis – Ghon's Complex

Refer to Chapter: Infectious Diseases

• Components: Ghon focus (subpleural caseous nodule in lower/upper lobe) + Lymphangitis + Hilar lymph node caseation.

Morphology: Subpleural, 1 to 2 centimeters, yellow-white caseous.

· Fate: Heals by fibrosis/calcification (Ranke complex), or progresses to progressive/miliary T.B.

4. Hypothyroidism

Refer to Chapter: Endocrine System

• Types: Primary (thyroid failure), Secondary (pituitary failure), Tertiary (hypothalamic).

· Etiology: Hashimoto thyroiditis (most common), iodine deficiency, post-ablative.

· Morphology (Hashimoto): Firm, pale thyroid, lymphoid follicles with germinal centers, Hürthle cell change.

· Clinical: Myxedema (non-pitting edema), bradycardia, cold intolerance, mental slowness.

Variant 23

1. D.I.C Syndrome (Disseminated Intravascular Coagulation)

Refer to Chapter: Haematopoietic System – Haemostatic Disorders

- · Definition: Widespread activation of coagulation leading to microthrombi + consumption of platelets/clotting factors to bleeding.

- · Etiology: Sepsis, trauma, obstetric complications, malignancies.

- Morphology: Microthrombi in small vessels (kidney, lung, brain). Hemorrhages.

- · Lab: Low platelets, prolonged P.T/P.T.T, low fibrinogen, elevated D-dimer.

2. Cancer of Colon. Tumors of Small Intestine

Refer to Chapter: G.I.T

- · Colon Cancer: Adenocarcinoma arising from adenomatous polyps. Left colon (annular, obstructive) versus Right colon (polypoid, bleeding).

- · Tumors of Small Intestine: Rare. Adenocarcinoma (duodenum), carcinoid (ileum – most common net), lymphoma, gist.

3. Cerebral Infarction

Refer to Chapter: Nervous System

• Types: Ischemic (thrombotic/embolic) – 80%; Hemorrhagic (10 to 15%).

· Morphology (Ischemic):

· 0–48h: Softening, blurring of gray-white junction.

· 2 to 10 days: Opaque, swollen, gelatinous tissue.

· Weeks: Liquefactive necrosis leads to cystic cavity.

4. Endemic Parotitis (Mumps)

Refer to Chapter: Infectious Diseases

· Etiology: Paramyxovirus.

• Pathogenesis: Droplet transmission leads to viremia, which targets salivary glands (especially parotid).

· Morphology: Bilateral parotid swelling, interstitial inflammation (lymphocytes, macrophages). No suppuration.

• Complications: Orchitis (males), pancreatitis, meningitis.

Var 01

1. Wound Healing

Refer to Chapter: Inflammation & Repair

• Phases: Hemostasis leads to Inflammation leads to Proliferation (granulation tissue, epithelialization) leads to Remodeling (collagen maturation).

- Types: Primary intention (clean incision) versus Secondary intention (wound gaping, more granulation, larger scar).

2. Tumor Definition. W.H.O Classification

• Tumor Definition: Abnormal mass of tissue with uncontrolled growth, exceeds normal tissue, persists after stimulus removal.

· W.H.O Classification: Based on histogenesis (cell of origin):

· Epithelial leads to Carcinoma

· Mesenchymal leads to Sarcoma

· Lymphoid leads to Lymphoma/Leukemia

• Germ cell leads to Teratoma, etcetera

3. Aplastic Anemia

Refer to Chapter: Haematopoietic System

· Definition: Failure of bone marrow hematopoiesis leads to pancytopenia.

· Etiology: Idiopathic, drugs (chloramphenicol), chemicals (benzene), radiation, viruses.

· Morphology: Fatty marrow (hypocellular). Peripheral blood: pancytopenia (normocytic normochromic).

• Outcomes: Infection, bleeding, transformation to M.D.S/leukemia.

4. Bacterial and Protozoal Infection

· Bacterial: Pyogenic (abscess), granulomatous (T.B, leprosy), toxin-mediated.

• Protozoal: Malaria (hemozoin pigment, splenomegaly), Amoebiasis (flask-shaped ulcer), Toxoplasmosis.

V-5

1. Atrophy: Definition, Etiology, Pathogenesis, Classification, Morphological Features, Outcomes Refer to Chapter: Cell Injury

- Definition: Shrinkage of organ/cell size after normal growth.

- · Etiology: Disuse, denervation, ischemia, malnutrition, pressure, hormone loss, aging.

• Pathogenesis: Decreased protein synthesis + increased ubiquitin-proteasome degradation.

- · Morphology: Brown atrophy (lipofuscin pigment), reduced organ size.

• Outcomes: Reversible if cause removed; irreversible leads to fibrosis.

2. T.N.M System. Grading and Staging of Tumors

Refer to Chapter: Neoplasia

- · T.N.M: T (tumor size/extent), N (lymph node involvement), M (metastasis).

- · Grading: Histological (low grade = well differentiated; high grade = poorly differentiated).

- · Staging: Clinical/anatomical extent (Stage 1 to 4). More prognostic than grading.

3. Chronic Peptic Ulcer: Definition, Epidemiology, Etiology, Pathogenesis, Morphological Features, Complications Refer to Chapter: G.I.T

- Definition: Chronic mucosal break penetrating muscularis mucosa.

- · Epidemiology: Duodenal (more common) greater than Gastric. H. pylori in approximately 70%.

- · Etiology: H. pylori, N.S.A.I.D's, hyperacidity, smoking.

- Morphology: Round/oval, sharply punched-out, fibrotic base, raised margins.

• Complications: Bleeding, perforation, obstruction, carcinoma (gastric ulcer only).

4. Intracellular Accumulation of Proteins: Types, Etiology, Morphology, Outcomes. Tyrosinosis, Phenylketonuria Refer to Chapter: Cell Injury

· Protein Accumulation:

· Reabsorption droplets (renal tubules in proteinuria) – hyaline droplets.

• Russell bodies (plasma cells) – immunoglobulins.

· Alpha-1 antitrypsin deficiency – hepatocytes.

· Tyrosinosis: Defect in tyrosine metabolism leads to liver/kidney damage, crystals.

• Phenylketonuria (P.K.U): Defect in phenylalanine hydroxylase leads to brain damage, fair skin.

---

Variant 28

1. Portal Hypertension

Refer to Chapter: Liver

- · Definition: Increased portal pressure ( greater than 10 mmHg).

- Causes: Prehepatic (portal vein thrombosis), Intrahepatic (cirrhosis – most common),

- Posthepatic (Budd-Chiari).

- Morphology: Esophageal varices, splenomegaly, ascites, caput medusae.

2. Tumour of Endometrium and Myometrium

- · Endometrial: Endometrioid adenocarcinoma (most common, bleeding, hyperplasia precursors). Endometrial polyp (benign).

- · Myometrium: Leiomyoma (fibroid-benign, whorled, estrogen-dependent) versus Leiomyosarcoma (malignant, necrosis, mitoses).

3. Chronic I.H.D (Ischemic Heart Disease)

Refer to Chapter: Cardiovascular

· Definition: Myocardial ischemia due to chronic coronary atherosclerosis.

Morphology: Myocyte hypertrophy, interstitial fibrosis, diffuse patchy fibrosis.

• Outcome: Heart failure, arrhythmias.

4. Apoptosis

Already answered in previous response.

--- Var 39 1. Hemosiderosis, Hemochromatosis, Porphyria Already answered in previous response.

2. Benign and Malignant Tumors of Fibrous Tissue

Benign Malignant Tumor Fibroma Fibrosarcoma Morphology Well-circumscribed, collagen bundles Infiltrative, herringbone pattern, mitoses Other Desmoid (aggressive fibromatosis) – locally invasive Rare

3. Thalassemia

Already answered in previous response.

4. Acute Gastric Ulcer, Symptomatic Ulcers

Already answered in previous response.

Let me know if you need a specific topic expanded further.

Here are the answers for your additional variants, strictly according to Harsh Mohan's Textbook of Pathology.

Variant 30

1. Acute and Chronic Congestion in Pulmonary Circulation

Refer to Chapter: Haemodynamic Disorders Feature Acute Pulmonary Congestion Chronic Pulmonary Congestion Etiology Acute 55 failure (M.I, mitral regurgitation) Chronic 55 failure (mitral stenosis, H.T.N, I.H.D) Morphology Heavy, wet lungs. Capillary engorgement, intra-alveolar edema fluid. Brown induration of lungs. Alveolar septal thickening, heart failure cells (hemosiderin-laden macrophages).

Outcome Acute respiratory distress Fibrosis, dyspnea

2. Acute and Chronic Adrenocortical Insufficiency (Addison's Disease)

Refer to Chapter: Endocrine System Acute (Adrenal Crisis):

- · Etiology: Waterhouse-Friderichsen syndrome (meningococcemia), sudden steroid withdrawal, adrenal hemorrhage.

- · Morphology: Bilateral hemorrhagic necrosis of adrenals.

- · Clinical: Hypotension, shock, D.I.C.

Chronic (Addison's Disease):

- · Etiology: Autoimmune (70%), T.B (prior), metastatic carcinoma, amyloidosis.

- Morphology: Atrophic/destroyed adrenals (T.B: caseous necrosis; autoimmune: lymphocytic infiltration).

- · Clinical: Hyperpigmentation (↑A.C.T.H), hyponatremia, hyperkalemia, hypotension, fatigue.

3. Cardiomyopathies: Types, Etiology

Refer to Chapter: Cardiovascular System

Type Features Etiology

Dilated (D.C.M) Dilated 55, systolic dysfunction, "flabby heart" Idiopathic, alcohol, viral (Coxsackie), peripartum, genetic Hypertrophic (H.C.M) Asymmetric septal hypertrophy, diastolic dysfunction, small L.V cavity Autosomal dominant (sarcomere mutations – beta myosin)

Restrictive (R.C.M) Stiff, non-compliant ventricle, normal size Amyloidosis, sarcoidosis, hemochromatosis, endomyocardial fibrosis

4. Diseases of Cervix

Refer to Chapter: Female Genital Tract

- · Cervicitis: Acute (gonorrhea, chlamydia) – purulent; Chronic – follicular cervicitis (lymphoid follicles).

- · Cervical Polyp: Benign, friable, can bleed.

- Cervical Intraepithelial Neoplasia (C.I.N): Dysplasia (C.I.N 1 to 3). H.P.V 16,18.

- Cervical Carcinoma: Squamous cell carcinoma (80%) – arises from transformation zone.

Adenocarcinoma (20%).

1. Arterial Hyperemia: Definition, Classification, Types, Morphology Refer to Chapter: Haemodynamic Disorders

- Definition: Increased blood volume in arteries and capillaries due to active arteriolar dilation.

• Classification:

- · Physiological: Exercise, digestion, blushing.

• Pathological: Inflammation (redness, heat).

- · Morphology: Affected tissue is red, warm, with increased blood flow. No edema (unlike congestion).

2. Anemias Due to Increased Red Cell Destruction (Hemolytic Anemias)

Refer to Chapter: Haematopoietic System

- · Etiology:

- · Intrinsic (Corpuscular): Membrane defects (spherocytosis), enzyme defects (G.6.P.D), hemoglobin defects (thalassemia, sickle cell).

- · Extrinsic (Extracorpuscular): Autoimmune (warm/cold A.I.H.A), microangiopathic (T.T.P, D.I.C), infections (malaria), drugs.

Mechanisms of Hemolysis:

· Intravascular: Hemoglobinemia, hemoglobinuria.

• Extravascular: Spleen/liver macrophages to jaundice, splenomegaly.

· Clinical Effects: Anemia, jaundice (unconjugated bilirubin), splenomegaly, gallstones, reticulocytosis.

· Sickle Cell Anemia: Mutation in beta globin (Glu 6 Val). HbS polymerizes in hypoxia leads to R.B.C sickle shape leads to vaso-occlusion, pain crises, autosplenectomy (hyposplenism).

3. Hyperplasia of Prostate Gland versus Cancer of Prostate Refer to Chapter: Male Genital Tract Feature Benign Prostatic Hyperplasia (B.P.H) Prostate Cancer Etiology Age + androgen (D.H.T) stimulation Genetic, androgen-related Location Transition zone Peripheral zone (70%)

Morphology Nodules, firm, circumscribed Hard, infiltrative, yellow-white Histology Glands with papillary tufts, corpora amylacea Small glands with infiltrative pattern, prominent nucleoli Lab diagnosis Not applicable P.S.A (elevated), Gleason grading Complications Obstruction, hydronephrosis, U.T.I Metastasis (bone – o steoblastic) Metastasis None Lymphatic + hematogenous (bone, liver, lung)

4. Syndrome of Liver Insufficiency and Portal Hypertension Liver Insufficiency (Hepatic Failure):

- · Etiology: Cirrhosis, viral hepatitis, toxins.

- · Morphology: Loss of hepatocytes, jaundice, coagulopathy, hypoalbuminemia, hepatic encephalopathy.

Portal Hypertension (already detailed in Variant 28 Q.1). Add:

- · Morphological characteristics: Esophageal varices, caput medusae, splenomegaly (congestive), ascites (protein-rich fluid), hemorrhoids.

--- Variant 11 1) Predisease, Norm

- Norm (Health): State of structural and functional integrity with ability to maintain homeostasis. Predisease (Latent phase): Stage with risk factors or subclinical changes without overt symptoms/disease. Example: Atherosclerosis before M.I, C.I.N before carcinoma.

2) Venous Hyperemia Same as Venous Congestion (Billet 31 Q.1)

3) Acute Gastritis Refer to Chapter: G.I.T

- Definition: Acute mucosal inflammation of stomach.

- · Etiology: N.S.A.I.D's, alcohol, stress (Curling/Cushing ulcer), H. pylori (rarely acute), bile reflux.

- Morphology: Hyperemic, edematous mucosa, erosions (superficial, no fibrosis). Hemorrhagic if severe.

- · Histology: Neutrophil infiltration in surface epithelium.

4) Pain

- · Definition: Unpleasant sensory/emotional experience from actual/potential tissue damage.

• Mechanisms: Nociceptors arrow A delta (sharp) and C fibers (dull) arrow spinal cord arrow thalamus arrow cortex.

- Types: Somatic, visceral, neuropathic, referred.

---

Variant 8

1) Etiology Definition: Study of causes of disease. Categories:

- · Genetic (chromosomal, monogenic – for example, thalassemia)

- · Acquired (infectious, nutritional, chemical, physical, immunological, psychological)

2) Arterial Hyperemia Same as V.32 Q.1 3) Megaloblastic Anemia (Vitamin B.12)

Refer to Chapter: Haematopoietic System

- · Etiology of B.12 deficiency: Pernicious anemia (autoimmune – lack of intrinsic factor),

- gastrectomy, malabsorption (Crohn's), vegetarian diet.

- Morphology (Bone marrow): Hypercellular, megaloblasts (large, immature R.B.C precursors with "nuclear-cytoplasmic asynchrony").

- Blood picture: Macrocytic anemia (M.C.V greater than 100 fl), hypersegmented neutrophils ( greater than 5 lobes).

- Anisopoikilocytosis.

- · Clinical: Anemia, subacute combined degeneration of spinal cord (posterior + lateral columns).

4) Diarrhea and Constipation

Diarrhea: Increased stool frequency/water content ( greater than 200g/day). Types: Osmotic, secretory, exudative (inflammatory), altered motility.

• Constipation: Hard, infrequent stools ( less than 3/week). Etiology: Low fiber, drugs (opioids), obstruction, hypothyroidism.

Variant 24 1) Dysplasia: Definition, Morphological Characteristic, Role in Carcinogenesis Refer to Chapter: Neoplasia

• Definition: Abnormal, non-neoplastic proliferation with loss of cellular uniformity and architectural orientation. Reversible.

Morphology: Pleomorphism, hyperchromatic nuclei, increased mitoses (some atypical), loss of polarity.

· Role in carcinogenesis: Precursor/preinvasive stage of carcinoma (e.g., C.I.N, dysplasia in Barrett's esophagus). Progression to carcinoma in situ then invasive cancer.

2) Hypo and Hyper Pituitary Refer to Chapter: Endocrine System Hypopituitarism Hyperpituitarism Etiology Pituitary adenoma (compression), Sheehan syndrome (postpartum necrosis), trauma, T.B Pituitary adenoma (functional) – lactotroph (prolactin), somatotroph (G.H), corticotroph (A.C.T.H) Morphology Atrophic pituitary Chromophobe/eosinophilic/basophilic adenoma. Sellar enlargement Clinical Pallor, hypogonadism, hypothyroidism, adrenal insufficiency Prolactin leads to galactorrhea; G.H leads to acromegaly/gigantism; A.C.T.H leads to Cushing disease 3) Cerebrovascular Diseases: Definition, Etiology, Classification Refer to Chapter: Nervous System

- · Definition: Diseases of brain blood vessels leading to ischemia, infarction, or hemorrhage.

- · Etiology: Atherosclerosis (main), hypertension, embolism (cardiac), vasculitis, amyloid

- angiopathy.

- Classificat ion:

- · Ischemic (80%): Thrombotic (large vessel, lacunar), embolic (cardioembolism)

• Hemorrhagic (15%): Intracerebral (H.T.N), subarachnoid (berry aneurysm rupture)

4) Scarlet Fever: Etiology, Pathogenesis, Morphological Characteristics, Complications, Outcomes

· Etiology: Group A beta-hemolytic Streptococcus pyogenes (erythrogenic toxin-producing strains).

• Pathogenesis: Toxin-mediated (not invasion). Toxin causes rash + systemic symptoms.

Morphology:

• Tongue: "Strawberry tongue" (red, papillae prominent).

· Skin: Sandpaper rash (fine, punctate erythema), Pastia lines (linear petechiae in folds), desquamation later.

Pharynx: Acute tonsillopharyngitis (exudative).

• Complications: Suppurative (peritonsillar abscess, otitis), nonsuppurative (rheumatic fever, post-streptococcal G.N).

• Outcomes: Self-limited (1 week) with antibiotics; otherwise risk of rheumatic fever.

--- Billet 35 Pyelonephritis Refer to Chapter: Urinary System

- Acute: Suppurative inflammation of kidney (tubulointerstitial) due to ascending infection (E. coli). Morphology: Focal abscesses, neutrophilic casts ("pus casts"), papillary necrosis. Chronic: Chronic tubulointerstitial inflammation + scarring. Morphology: Coarse, asymmetric scars, blunted calyces.

M.I (Myocardial Infarction)

Refer to Chapter: Cardiovascular

- · Definition: Coagulative necrosis of myocardium due to prolonged ischemia (coronary thrombosis).

- Morphology (timeline):

- · 0–4h: None (T wave changes)

- 4–24h: Pallor/dark mottling

- · 1 to 7 days: Yellow, soft (neutrophils)

- · 7 to 10 days: Red border (granulation tissue)

- · Weeks: White scar

Liver Cirrhosis

- Definition: Diffuse fibrosis + nodular regeneration.

- Morphology: Small/large nodules, fibrous septa. Micronodular (alcohol), Macronodular (post-necrotic), Mixed.

• Consequences: Portal hypertension + liver failure.

Nucleic Acid Metabolism Disorder

- · Gout: Hyperuricemia to urate crystal deposition. Morphology: Tophi (periarticular, ear), needle-shaped crystals. Acute arthritis, chronic tophaceous gout.

- · Lesch-Nyhan syndrome: H.G.P.R.T deficiency (X-linked) leads to self-mutilation, choreoathetosis, hyperuricemia.

Urolithiasis and Cholelithiasis

· Urolithiasis: See Billet 31 Q.4.

· Cholelithiasis (Gallstones):

· Cholesterol stones (most common in West) – radiolucent.

· Pigment stones (calcium bilirubinate – hemolytic anemia) – radiopaque.

• Mixed stones.

Pancreatic Tumors

Refer to Chapter: G.I.T – Pancreas

- · Adenocarcinoma (Ductal, 85 to 90%): Head (obstructive jaundice), hard, infiltrative. Microscopic: glands with desmoplasia. Very poor prognosis.

- · Neuroendocrine tumors (Pancreatic net): Insulinoma, gastrinoma (Zollinger-Ellison), glucagonoma.

Thrombophlebitis

• Inflammation of vein (phlebitis) + thrombosis. Morphology: Red, tender cord, thrombus attached to vein wall. Risk: Virchow's triad.

Nephrotic Syndrome Refer to Chapter: Urinary System

· Definition: Proteinuria ( greater than 3.5g/24h), hypoalbuminemia, edema, hyperlipidemia.

· Morphology (major causes):

• Minimal change disease (foot process effacement – normal L.M)

• Membranous nephropathy (subepithelial spikes – most common adult)

· F.S.G.S (focal segmental sclerosis)

• Membranoproliferative G.N (tram-track appearance)

Let me know if you need further elaboration on any specific topic.

Here are the short answers for Billet No. 41 according to Harsh Mohan.

1) Iron-containing and Non-iron-containing Pigments

Iron-containing (Hemosiderin)

- Color: Golden-brown

- · Stain: Prussian blue (+)

- Example: Old hemorrhage, hemochromatosis

Non-iron-containing Pigment Color Example

- Lipofuscin Golden-brown Aging (heart, liver)

- Melanin Brown-black Skin, melanoma

- Bilirubin Yellow-green Jaundice

- Carbon Black Anthracosis (lung)

---

2) Acute Leukemias

- Definition: Malignant proliferation of blasts in blood & bone marrow.

• Classification: A.L.L (lymphoid) vs A.M.L (myeloid)

- Blood picture: Pancytopenia + circulating blasts

• Bone marrow: Hypercellular ( greater than 20 to 30% blasts) • Key feature: Auer rods = A.M.L (diagnostic)

3) Types of Alcoholic Liver Disease

Type Morphology Outcome Fatty liver Macrovesicular steatosis Reversible Alcoholic hepatitis Ballooning, Mallory bodies, neutrophils May progress Cirrhosis Micronodular to macronodular Irreversible; liver failure

4) Renal Failure

Acute Renal Failure (A.R.F) Chronic Renal Failure (C.R.F) Etiology Prerenal, renal (A.T.N), postrenal Diabetes, H.T.N, G.N Morphology Swollen kidney, tubular necrosis Small, shrunken, granular kidney Outcome Potentially reversible Irreversible (dialysis/transplant)

Let me know if you need other billet answers in short form.

1. Patho of Inflammation (Harsh Mohan, Ch. Inflammation)

Acute: Vasodilation leads to increased permeability leads to neutrophil exudation leads to pus / edema. Chronic: Lymphocytes, plasma cells, macrophages leads to fibrosis plus or minus granuloma. Chemical mediators: Histamine, prostaglandins, leukotrienes, cytokines.

2. Endogenous Pigments (Harsh Mohan, Ch. Cell Injury)

Pigment Color Key point Lipofuscin Golden-brown "Wear & tear" – aging heart/liver Melanin Brown-black ↑ in Addison's, ↓ in vitiligo Hemosiderin Golden-brown Iron; Prussian blue (+) – old hemorrhage Bilirubin Yellow-green Jaundice Hemozoin Brown-black Malaria pigment in spleen 3. Lobar Pneumonia (Harsh Mohan, Ch. Respiratory) · Cause: Streptococcus pneumoniae · Stages: Congestion to Red hepatization to Grey hepatization to Resolution · Gross: Affected lobe equals firm, airless, liver-like · Complications: Abscess, empyema, organization 4. Tumors of Blood & Lymphatic Vessels (Harsh Mohan, Ch. Blood Vessel) Blood vessels Lymphatic vessels Benign Hemangioma, Glomus tumor Lymphangioma, Cystic hygroma Malignant Angiosarcoma Lymphangiosarcoma Intermediate Kaposi sarcoma (H.H.V-8) – Here are the short answers according to Harsh Mohan's Textbook of Pathology.

1. Gallstones & Urinary Stones

(Refer: Chapter 19 Liver & Chapter 20 Kidney)

Feature Gallstones (Cholelithiasis) Urinary Stones (Urolithiasis) Common Types Mixed (64.6%), Cholesterol (23.5%) Calcium oxalate (most common), Uric acid, Struvite Composition Cholesterol + bilirubin + calcium salts Calcium oxalate/phosphate, uric acid, cystine Morphology Mixed: multifaceted, alternate dark/pale areas Calcium: hard, radiopaque; Uric acid: smooth, radiolucent Location Gallbladder Upper tract (kidney, ureter) or Lower tract (bladder) Complications Chronic cholecystitis, pancreatitis, G.B carcinoma (↑ with stones) Hydronephrosis, pyelonephritis, renal failure Key Point: Mixed stones are most common in North India. Pigment stones are associated with hemolysis and carcinoma.

2. Thrombophlebitis versus Phlebothrombosis (Refer: Chapter 11 Blood Vessels and Lymphatics)

Feature Phlebothrombosis Thrombophlebitis Definition Thrombosis in deep veins without inflammation Thrombosis with inflammation of vein wall Primary Process Thrombosis Inflammation (secondary thrombosis)

Site Deep veins of calf (D.V.T) Superficial or deep veins Thrombus Adhesion Loosely attached Firmly attached to wall Embolism Risk High (silent, may first present as P.E) Low (thrombus adherent)

Etiology Virchow's triad: stasis, vessel injury, hypercoagulability (post-op, C.H.F, obesity, O.C.P)

Infection, trauma, thromboangiitis obliterans, malignancy (pancreas, stomach)

Outcome Pulmonary embolism Recanalization, valve destruction (post-phlebitic syndrome)

3. Nephrotic Syndrome

(Refer: Chapter 20 Kidney)

Definition: Proteinuria ( greater than 3.5g/24h), hypoalbuminemia, edema, hyperlipidemia.

Common Causes (by age):

Age Group Most Common Cause

- Children Minimal Change Disease (lipoid nephrosis)

- Adults Membranous Nephropathy

- Elderly / Systemic Amyloidosis, Diabetes, S.L.E

Morphology:

• Minimal Change: Normal light microscopy, foot process effacement on E.M.

• Membranous: Spike and dome pattern (subepithelial deposits).

· F.S.G.S: Focal + segmental sclerosis, IgM + C.3.

Clinical Features:

- Oedema (periorbital in children, ankle in adults)

- · Urine: Protein (80 to 95 percent albumin), hyaline casts, plus or minus R.B.C's

- Blood: Hypoalbuminemia, hyperlipidemia (milky serum)

Complications: Infections (loss of Ig), thrombosis (loss of antithrombin 3), Renal failure.

4. Tumors of Pancreas

(Refer: Chapter 19 Liver, Biliary Tract & Exocrine Pancreas)

A. Exocrine Tumors (Most common)

- · Ductal Adenocarcinoma (85 to 90%):

- · Location: Head (60 to 70 percent) to obstructive jaundice.

- · Morphology: Hard, infiltrative, desmoplastic (firm, gritty). Microscopic: glands with dense stroma.

- · Spread: Perineural, lymphatic, liver.

- · Prognosis: Very poor.

B. Endocrine Tumors (Pancreatic net)

- · Less common, better prognosis.

Tumor Hormone Clinical Insulinoma Insulin Hypoglycemia (Whipple's triad)

Gastrinoma Gastrin Zollinger-Ellison syndrome (multiple ulcers)

Glucagonoma Glucagon Diabetes, necrolytic migratory erythema

C. Cystic Tumors

- Serous Cystadenoma: Benign, microcystic.

- · Mucous Cystadenoma / Cystadenocarcinoma: Malignant potential.

D. Solid and Cystic Papillary Neoplasm

- · Low malignant potential, occurs in young females (Harsh Mohan has published on this).

1. Rubella (German Measles)

(Refer: Chapter 7 Infectious Diseases)

A. Acquired Rubella

- · Etiology: R.N.A virus, Togaviridae family.

- · Pathogenesis: Droplet infection leads to respiratory epithelium leads to lymph nodes leads to viremia leads to skin rash.

- Morphology: Maculopapular rash, postauricular/occipital lymphadenopathy.

- · Outcome: Self-limiting, benign.

B. Congenital Rubella Syndrome (C.R.S)

- · Pathogenesis: Maternal infection in 1st trimester leads to transplacental infection, which leads to fetal vasculitis, tissue necrosis, and mitosis inhibition.

- Classic Triad: Cataracts, Cardiac defects (P.D.A, pulmonary stenosis), Sensorineural deafness.

- · Other features: Blueberry muffin rash (dermal erythropoiesis), microcephaly,

hepatosplenomegaly, thrombocytopenia.

- · Prevention: M.M.R vaccination pre-conception.

2. Infarction

(Refer: Chapter 5 Haemodynamic Disorders)

Definition: Area of ischemic necrosis caused by occlusion of arterial supply or venous drainage.

Types:

Feature Red (Hemorrhagic) Infarct White (Anemic) Infarct Tissue Loose/spongy (lung, liver, intestine) Solid/compact (heart, kidney, spleen)

Blood supply Dual supply or collateral circulation End-artery occlusion Morphology Wedge-shaped, red-dark, hemorrhagic Wedge-shaped, pale, firm Morphology (Timeline - Kidney/Heart):

- · 0-12h: No gross change.

- · 12-24h: Pallor, slight swelling.

- · 24-48h: Soft, pale, hemorrhagic rim.

- · 3 to 10 days: Yellow-white, soft, hyperemic border.

- · 10 days-6 weeks: Liquefactive necrosis to cystic cavity (brain) or fibrous scar (heart/kidney).

3. Cerebral Tumors

(Refer: Chapter 28 Nervous System)

Classification (Based on Histogenesis):

Cell of Origin Tumor Type

- Neuroepithelial Astrocytoma, Oligodendroglioma, Ependymoma, Glioblastoma multiforme (Grade 4)

- Meningothelial Meningioma (benign, most common primary C.N.S tumor in adults)

- Neuronal Gangliocytoma, Ganglioglioma

- Embryonal Medulloblastoma (children, cerebellum)

- Peripheral nerve Schwannoma (acoustic neuroma), Neurofibroma

- Pituitary Pituitary adenoma

- Germ cell Germinoma, Teratoma

W.H.O Grading :

- · Grade 1: Benign, slow-growing (Pilocytic astrocytoma)

- · Grade 2: Low-grade infiltrative

- · Grade 3: Anaplastic, mitotically active

- Grade 4: Malignant, necrosis, microvascular proliferation (Glioblastoma – Grade 4, less than 1 year survival)

Morphology: Primary tumors: intraparenchymal (gliomas) or extra-axial (meningioma). Metastatic tumors (lung, breast) usually at gray-white junction.

4. Septic Myocarditis (Refer: Chapter 12 The Heart)

Definition: Myocardial inflammation due to bacterial infection – part of infective endocarditis or sepsis.

Pathogenesis: Hematogenous spread (bacteremia) leads to myocardial microabscesses.

Morphology:

- Gross: Multiple small yellow-white abscesses scattered in myocardium.

- · Microscopic: Foci of suppurative inflammation (neutrophils), with central bacterial colonies, surrounded by necrotic myocytes and hyperemic border.

Causes: Staphylococcus aureus (most common), Streptococcus, Salmonella (typhoid myocarditis).

Outcome: Arrhythmias, cardiac failure, septic shock, death.

Let me know if you need any other variants.

Here are the short answers according to Harsh Mohan's Textbook of Pathology.

1. Thyroiditis

Acute (Suppurative) Thyroiditis

- · Etiology: Bacterial infection (Staph, Strep, E. coli).

- · Morphology: Abscess formation, neutrophilic infiltration.

- · Clinical: Painful, tender, fever; rare.

Subacute (De Quervain's) Granulomatous Thyroiditis

· Etiology: Viral (mumps, coxsackie, E.B.V, post-covid).

· Epidemiology: Females 30 to 50 years (F:M = 3 to 5:1), summer/autumn peak.

· Pathogenesis: Viral-induced inflammation leads to follicular disruption leads to release of preformed thyroid hormone .

Morphology: Patchy involvement, giant cells engulfing colloid, epithelioid cells, fibrosis.

· Clinical Course (4 phases): Thyrotoxic (3 to 6 weeks) to Euthyroid to Hypothyroid to Recovery .

· Lab: High T.4/T.3, Low R.A.I.U, High E.S.R, negative autoantibodies.

• Outcome: Self-limiting (weeks-months).

Chronic Lymphocytic (Hashimoto's) Thyroiditis

- · Etiology: Autoimmune (anti-T.P.O, anti-thyroglobulin).

- Morphology: Firm, pale thyroid. Lymphoid follicles with germinal centers, Hürthle cell change, atrophy.

- · Outcome: Hypothyroidism.

Riedel's (Invasive Fibrous) Thyroiditis

- · Etiology: Unknown (I.g.G.4-related).

- Morphology: Wood-hard thyroid, dense fibrosis extending into surrounding tissues.

--- 2. Benign and Malignant Tumours of Adipose Tissue (Refer: Harsh Mohan, Chapter 29 Soft Tissue Tumours)

Benign Malignant

Tumour Lipoma (most common soft tissue tumour) Liposarcoma Epidemiology Adults 40 to 60 years Adults 40 to 60 years Morphology Soft, yellow, encapsulated. Mature adipocytes, normal cytology. Large, deep-seated, poorly defined.

Subtypes Conventional (common), Intramuscular, Angiolipoma, Hibernoma (brown fat). Myxoid (most common), Well-differentiated (atypical lipomatous), Pleomorphic, Dedifferentiated.

Prognosis Excellent; excision is curative. Metastasis (lungs, liver); low-grade: 2 to 10%, high-grade: 20 to 100%.

3. Pulmonary Emphysema

(Refer: Harsh Mohan, Chapter 17 Respiratory System)

Definition: Abnormal, permanent enlargement of airspaces distal to terminal bronchioles with destruction of alveolar walls (no fibrosis).

Pathogenesis: Protease-antiprotease imbalance (smoking leads to neutrophil elastase; alpha 1-antitrypsin deficiency).

Types & Morphology:

Type Location Association Key Morphology Centriacinar Upper lobes, apices Smoking (most common) Central respiratory bronchioles dilated; spared peripheral alveoli Panacinar Lower lobes, bases 1 -antitrypsin deficiency Whole acinus uniformly enlarged Paraseptal Subpleural (lung fissures) Spontaneous pneumothorax Multiple, subpleural blebs/bullae Irregular Scars Post-inflammatory Associated with fibrosis Irregular Scars Post-inflammatory Associated with fibrosis Outcome: Progressive dyspnea, C-O 2 retention, cor pulmonale.

4. Type 1 Hypersensitivity (Immediate)

(Refer: Harsh Mohan, Chapter 4 Immunopathology)

Definition: IgE-mediated reaction occurring within minutes of antigen exposure.

Sequence:

1. Sensitization: First exposure to Allergen to B-cell to IgE to binds to mast cells (Fc epsilon R 1). 2. Activation: Re-exposure to cross-linking IgE to mast cell degranulation.

Mediators & Effects:

- · Primary (preformed): Histamine, Serotonin leads to vasodilation, increased permeability.

- · Secondary (newly formed): Leukotrienes (bronchospasm), Prostaglandins (pain, edema), P.A.F.

Clinical Manifestations:

- · Localized: Urticaria (hives), allergic rhinitis, bronchial asthma, angioedema.

- · Systemic: Anaphylaxis (shock, airway obstruction).

Treatment: Antihistamines, corticosteroids, epinephrine, desensitization.

1. Adenocarcinoma of Colon

Definition: Malignant epithelial tumor of colonic mucosa; most common histological type of colorectal cancer.

Classification (W.H.O):

- · Adenocarcinoma (N.O.S) – 90%

- · Mucinous adenocarcinoma – 5 to 10%

- · Signet ring cell carcinoma – rare

- · Other variants: Medullary, Serrated, Micropapillary

Morphology:

- · Gross: Polypoid, ulcerating, or annular ("napkin-ring") lesion

- Microscopy: Malignant glands with cribriform pattern, nuclear stratification, desmoplasia

- · Grading (Duke's/Modified): Grade 1 (well-differentiated) to Grade 4 (undifferentiated)

Spread: Local invasion to Lymphatic (mesenteric nodes) to Hematogenous (liver greater than lung)

Associated conditions: Familial adenomatous polyposis (F.A.P), Lynch syndrome (H.N.P.C.C), I.B.D

2. Acute and Chronic Venous Pulmonary Congestion

Acute Pulmonary Congestion

- · Etiology: Acute left ventricular failure (M.I, mitral regurgitation)

- Morphology: Heavy, wet lungs; capillary engorgement; intra-alveolar edema fluid

- · Clinical: Acute dyspnea, pink frothy sputum

Chronic Pulmonary Congestion

· Etiology: Chronic left heart failure (mitral stenosis, hypertension, I.H.D)

· Morphology: Brown induration of lungs – firm, brownish lungs

• Microscopy: Alveolar septal thickening (fibrosis), heart failure cells (hemosiderin-laden macrophages in alveoli)

• Outcome: Dyspnea, pulmonary hypertension, cor pulmonale

3. Addison's Disease (Acute and Chronic Adrenocortical Insufficiency)

Acute Adrenal Crisis (Waterhouse-Friderichsen syndrome)

- · Etiology: Meningococccemia, septic shock, adrenal hemorrhage, sudden steroid withdrawal

- Morphology: Bilateral hemorrhagic necrosis of adrenals

- · Clinical: Hypotension, shock, D.I.C, purpura, death

Chronic Addison's Disease

- · Etiology: Autoimmune (70%) – most common; Tuberculosis (prior), metastatic carcinoma, amyloidosis

Morphology:

- · Autoimmune: Atrophic adrenals, lymphocytic infiltration

- Tuberculous: Caseous necrosis, calcification

- · Clinical (symptoms greater than 90%): Hyperpigmentation ( A.C.T.H), weakness, fatigue, anorexia, weight loss, hypotension, salt craving, hypoglycemia

- · Lab: Low cortisol, high A.C.T.H, hyponatremia, hyperkalemia

- Diagnosis: A.C.T.H stimulation test (peak cortisol less than 18 mcg/dL)

- · Treatment: Hydrocortisone + Fludrocortisone replacement

4. Cardiomyopathy

Definition: Heterogeneous group of myocardial disorders with structural and functional abnormality, excluding C-A-D, hypertension, valvular, or congenital heart disease.

Classification (based on morphology/phenotype):

Type Morphology Key Features Dilated (D.C.M) Dilated 55 or biventricular, systolic dysfunction, "flabby heart" Most common cause of H.F; idiopathic, genetic, alcohol, viral (Coxsackie), peripartum Hypertrophic (H.C.M) Asymmetric septal hypertrophy, diastolic dysfunction, small L.V cavity Most common genetic cardiomyopathy; sarcomere mutations; risk of sudden cardiac death Restrictive (R.C.M) Stiff, non-compliant ventricles, normal size, dilated atria Rare; amyloidosis (most common), sarcoidosis, hemochromatosis Arrhythmogenic (A.R.V.C) Fibrofatty replacement of R.V myocardium Desmosomal gene mutations; arrhythmias, S.C.D in young Primary vs Secondary Cardiomyopathies:

- · Primary: Heart alone involved (genetic, acquired, mixed)

- Secondary: Part of systemic disease (infiltrative, storage, toxic, endocrine, inflammatory)

Clinical: Heart failure, arrhythmias, sudden death; H.C.M is the most common inherited cause of S.C.D in young athletes.

5. Diseases of Cervix

Classification of Cervical Lesions :

A. Inflammatory (most common – 74%):

- · Acute cervicitis: Neutrophilic infiltration (gonorrhea, chlamydia)

- Chronic cervicitis: Lymphocytes, plasma cells; may show squamous metaplasia, Nabothian cysts

B. Benign:

- · Endocervical polyp (most common benign – 79%)

- · Leiomyomatous polyp, fibroepithelial polyp

C. Precursor Lesions (Cervical Intraepithelial Neoplasia – C.I.N):

- · L-S.I.L (C.I.N 1): Mild dyspla sia, koilocytosis (H.P.V effect)

- · H-S.I.L (C.I.N 2 to 3): Moderate to severe dysplasia

- · Role in carcinogenesis: Progression to invasive carcinoma if untreated

D. Malignant:

- · Squamous cell carcinoma (92%): Most common; arises from transformation zone; H.P.V 16, 18 associated

- · Subtypes: Large cell non-keratinizing (most common), Large cell keratinizing

- · Adenocarcinoma (5 to 8%): Mucinous, villoglandular, endometrioid

- · Sarcomatoid carcinoma: Rare variant

Clinical Correlation: Early detection via Pap smear leads to prevents progression to invasive cancer.

Biopsy remains the gold standard for diagnosis.

Let me know if you need additional variants.

Here are the short answers for Billet 40 according to Harsh Mohan.

1. Immunodeficiency

• Definition: Defect in immune response leads to increased infections.

· Primary (congenital): Bruton (B-cell), DiGeorge (T-cell), S.C.I.D.

· Secondary (acquired): AIDS, malnutrition, chemotherapy.

· AIDS: H.I.V leads to C.D.4 plus T-cell loss leads to opportunistic infections (T.B, Pneumocystis), Kaposi sarcoma.

2. Hemoblastoses

- Definition: Malignant tumors of blood-forming tissues.

- · Leukemias: Origin in bone marrow (A.L.L, A.M.L, C.L.L, C.M.L).

- · Lymphomas: Origin in lymph nodes/spleen (Hodgkin, Non-Hodgkin).

- · Plasma cell dyscrasias: Multiple myeloma.

- Blood picture: Blasts (acute), pancytopenia or leukocytosis.

• Bone marrow: Hypercellular, replaced by malignant cells.

3. Systemic Lupus Erythematosus (S.L.E)

- · Definition: Autoimmune (Type 3 hypersensitivity) – immune complex disease.

- · Epidemiology: Females 20 to 40 years (F:M = 9:1).

Morphology:

- · Kidney: Lupus nephritis (wire-loop lesions)

- · Heart: Libman-Sacks endocarditis

- Spleen: Onion-skin periarterial fibrosis

- · Skin: Malar (butterfly) rash

- · Lab: A.N.A (+ 95%), anti-d.s.D.N.A (specific), low C.3/C4.

4. Viral Hepatitis

Virus Transmission Chronic Key Morphology

- H.A.V Fecal-oral No Acidophil (Councilman) bodies

- H.B.V Blood, sexual, vertical Yes (5 to 10%) Ground-glass hepatocytes (H.B.s.A.g)

- H.C.V Blood Yes ( greater than 70%) Lymphoid aggregates, steatosis

- H.E.V Fecal-oral No Severe in pregnancy

- Acute: Ballooning degeneration, lobular disarray.

- · Chronic: Interface hepatitis (piecemeal necrosis) leads to cirrhosis.

--- Let me know if you need more variants.

Here are the short answers according to Harsh Mohan's Textbook of Pathology.

1. Tumor

(Refer: Chapter 8 – Neoplasia)

- Definition: Abnormal mass of tissue with excessive, uncoordinated, autonomous proliferation that persists after stimulus removal.

- · Two basic components: Parenchyma (tumor cells) + supportive stroma (C.T/blood vessels).

- · Naming: Benign = suffix "-oma". Malignant epithelial = carcinoma; malignant mesenchymal = sarcoma.

• Special categories: Mixed tumors, Teratomas (3 germ layers), Blastomas (embryonal – children), Hamartoma (disorganized mature tissue), Choristoma (ectopic normal tissue).

2. Aplastic Anemia

(Refer: Chapter 13 – Haematopoietic System)

- · Definition: Bone marrow failure leads to pancytopenia plus hypocellular marrow.

- · Causes: Idiopathic (most common), Fanconi anemia (congenital), radiation, chemicals (benzene), drugs (chloramphenicol, chemotherapy), viruses (hepatitis, E.B.V).

Morphology: Fatty marrow (hypocellular). Peripheral blood: pancytopenia (normocytic normochromic).

• Outcome: Infection, bleeding; may transform to M.D.S/leukemia.

3. Dysentery

(Refer: Chapter 20 – G.I.T & Chapter 7 – Infectious Diseases)

Feature Bacillary Dysentery (Shigellosis) Amoebic Dysentery Etiology Shigella (bacteria) Entamoeba histolytica (protozoa) Pathology Acute colitis Flask-shaped ulcers (submucosal spread) Morphology Diffuse mucosal inflammation, superficial ulcers, pseudomembrane Deep undermining ulcers, normal intervening mucosa Complications Toxic megacolon, perforation Liver abscess, chronic carriage

4. Wound Healing

(Refer: Chapter 6 – Inflammation & Healing)

• Phases:

1. Hemostasis (immediate)

2. Inflammation (0 to 3 days – neutrophils, macrophages)

3. Proliferation (3 to 14 days – granulation tissue, angiogenesis, epithelialization)

4. Remodeling (weeks–months – collagen maturation, scar contraction)

· Types:

• Primary intention: Clean incision, minimal gap, linear scar.

• Secondary intention: Wound gaping, more granulation tissue, larger scar.

Variant 22 Short Answers

1. Type 4 Hypersensitivity (Delayed-Type)

(Refer: Chapter 4 – Immunopathology)

- · Definition: T-cell mediated (not antibody), delayed reaction (24 to 72 hours).

- · Mechanism: Antigen leads to C.D 4 plus T cells (T h 1), which release cytokines (I F N gamma), which activate macrophages

leads to tissue damage.

· Morphology: Perivascular lymphocytic infiltration leads to granuloma formation.

• Classic example: Tuberculosis (P.P.D test), contact dermatitis (poison ivy), allograft rejection.

2. Lung Cancer

(Refer: Chapter 17 – Respiratory System)

- · Most common: Bronchogenic carcinoma (95% of primary lung tumors).

- · W.H.O Classification (Major types):

Type Frequency Key Features Squamous cell 30 to 40% Central, cavitation, linked to smoking Small cell (oat cell) 20 to 25% Most aggressive, paraneoplastic syndromes Adenocarcinoma 30 to 40% Peripheral, most common in non-smokers Large cell 10 to 15% Undifferentiated, poor prognosis

• Spread: Lymphatic (hilar/mediastinal nodes), hematogenous (brain, bone, liver, adrenals).

3. Chickenpox and Herpes Zoster (Refer: Chapter 7 – Infectious Diseases)

Feature Chickenpox (Varicella) Herpes Zoster (Shingles)

Etiology Varicella-Zoster Virus (V.Z.V) – same virus Reactivation of latent V.Z.V Epidemiology Primary infection (usually children) Adults/immunocompromised Morphology Diffuse vesicular rash (different stages: "dewdrop on rose petal") Unilateral, dermatomal vesicular rash Pathogenesis Respiratory arrow viremia arrow skin Virus dormant in dorsal root ganglia arrow reactivation Complications Pneumonia, encephalitis Post-herpetic neuralgia

4. Trauma of C.N.S

(Refer: Chapter 28 – Nervous System)

• Primary (direct) injury: Occurs at moment of impact.

- Concussion: tran-zee-unt neurological dysfunction, no structural damage.

• Contusion: Bruising (coup = impact site; contrecoup = opposite side).

- Laceration: Tearing of brain tissue.

• Hemorrhage: Extradural (arterial – skull fracture), Subdural (venous – elderly/alcoholics),

Subarachnoid (trauma/aneurysm), Intracerebral.

- Secondary injury: Develops after impact leads to cerebral edema, increased I.C.P, hypoxia, ischemia, infection.

- · Clinical assessment: G.C.S (Eye, Verbal, Motor response).

Let me know if you need other variants.

You have reached the end of the document.