HISTOPATHOLOGY OSPE

Renal Amyloidosis

• Amorphous amyloid material occupying mesangium of glomerulus and walls of arterioles

• Thickening of glomerular basement membrane (amyloid deposition)

• Deposits can be nodular/diffused

• No inflammation (acellular)

• Thinning and dilated tubule walls

Hyaline Arteriosclerosis

• Hyalinization of arteries first then may affect glomerulus

• Narrowing artery lumen, thickening of artery walls

• Deposits can be nodular/diffused

• Tubular atrophy

• Interstitial fibrosis (interstitial deposits)

• Fibrinoid necrosis of small renal arteries

Diabetic Glomerulosclerosis

• Pink hyaline material in glomerular capillary loops

• Increase in mesangial matrix (damage as result of non-enzymatic glycosylation of proteins)

• Nodular = Kimmelstiel-Wilson lesion (usually focal, not entirely affects glomerulus)

• Diffuse = Basement of membrane of capillary loops, may affect arteries and tubules

Differentiate between 3 deposits

Look at clinical findings:

• If high immunoglobulin, renal amyloidosis

• If patient has hypertension and arteries are affected mainly, hyaline arteriosclerosis

• If patient is diabetic and glomerulus is affected mainly, diabetic glomerulosclerosis

Benign Prostatic Hyperplasia

• Rounded nodules of hyperplastic prostatic tissue

• Dilated hyperplastic glandular acini lined with tall columnar prostatic epithelial cells

• Papillary folds of hyperplastic cells

• Hypertrophy of fibromuscular tissues in bladder neck

• Corpora amylacea

Cervical Intraepithelial Neoplasia

• Enlarged, hyperchromatic, increased mitotic activity

• Koilocytes (enlarged irregular nuclei with clear cytoplasm)

• Stages:

  • 1: Lower epithelium only (most, confined to cervix)

  • 2: 2/3 of lower epithelium

  • 3: Entire epithelium, above basal cells

  • Invasive: Surface epithelium

• Nest of carcinoma within supporting stroma

• Surface of tumor is ulcerated alongside normal portion

• Keratin pearls (well differentiated)

Fibroadenoma of Breast

• Compressed ducts (glandular/cystic spaces lined by epithelium and enclosed by fibroelastic stromal component)

• Loose cellular stroma (with fibroblasts and pale collagen)

• Proliferation of both ducts (epithelium) and stroma

Ductal Carcinoma of Breast

• Epithelial cells fill and expand tubules

• Sharply defined glandular space

• Bridges of cells between space

Cirrhosis

• Regenerating nodules of liver cells between fibrous tissue bands

• Chronic inflammatory cells in fibrous tissue

• Bile duct proliferation

• Portal tracts separated by fibrous connective tissue proliferation

Hemochromatosis

• Some fibrosis due to inflammatory injury

• Some inflammatory cells

• Brown pigment accumulation especially in periportal area

Viral Hepatitis

• Inflammatory cell infiltrate, but not extended to other lobules (lymphocytic)

• Councilman bodies (apoptosis)

• Ballooning degeneration (apoptosis)

• Kuffer cell hyperplasia

• Caniculi cholestasis

• For chronic: Extends to the other lobules, and is much much worse with fibrosis.

Alcoholic Hepatitis/Fatty Liver Disease

• Inflammatory cell infiltrate (neutrophilic)

• Mallory bodies (red hyaline within hepatocytes)

• Fatty deposits (steatosis) in hepatocytes (micro/macrovesicular, push nucleus to the periphery)

Acute Appendicitis

• Inflammatory cell infiltrate (lumen, mucosa, muscularis, all by neutrophils)

• Mucosal necrosis (ulceration: lining completely replaced by debris)

• Fibrinopurulent exudate

Peptic Ulcer

• Coagulative necrosis of mucosa

• Infiltration of PMN (neutrophil, macrophage)

• Granulation tissue formation

• Chronic: Fibrous tissue beneath the ulcer

• Erosion: In NSAID use: Haemorrhage at ulcer base

• Extends into submucosa, loss of tissue

• Some mucosa not affected so can see normal mucosa beside the loss of lining

Colon Adenocarcinoma

• Irregular gland formation, lined with columnar cells

• Neoplastic glands are long, frond-like, exophytic growth

• May infiltrate submucosa, muscularis and fat layer

• Pleomorphic, hyperchromatism

Acute Purulent Meningitis

• Inflammatory cell infiltrate at meninges (Neutrophilic + Macrophages)

• Purulent exudate (neutrophil and bacteria) in subarachnoid space/leptomeninges

• Swelling of meninges

• Phlebitis (inflammation of blood vessels and thrombus)

• Blood vessels marginated with neutrophils, vasodilated

• Cortex and white matter may be spongy due to edema

Graves’ Disease

• Hyperplastia of follicular cells, causing papillary infolding into colloid with multiple layers

• Tall columnar epithelial cells

• Scalloping of colloid (clear vacuoles due to increased thyroid hormone production)

• Watery and depleted colloid

Hashimoto’s Thyroiditis

• Prominent lymphoid follicles with large, active germinal centers

• Lymphocyte infiltration

• Thyroid tissue replaced with lymphoid tissue

• May progress into scar tissue formation

• Reduced colloid

• Thyroid follicular cell metaplasia form Hurthle/Oxyphil cell (finely granular eosinophilic cytoplasm and enlarged nuclei)

  • Indication of progression to cancer due to constant inflammatory (stress)

Artherosclerosis

• Foam cell lesion with inflammatory cells (monocyte and lymphocyte)

• Cholesterol clefts

• Plaque formartion in artery, may/may not have recanalization, causing narrowing lumen

• May have thrombus (with hemorrhage)

• Lipid pools and lipid core in wall of artery

• Fibrous cap

• Intima thickening

• Smooth muscle cell proliferation and migration to tunica intima

• Proliferation of fibroblasts

Myocardial Infarction

• 2 – 24 hours: Contraction bands, edema, acute inflammation (few)

• 3 – 7 days: Coagulative necrosis (due to no lysosomal enzymes, decreased staining), neutrophilic infiltrate

• 1 – 3 weeks: Granulation tissue formation, myocytes replaced by tissue, macrophages prominent

• 3 – 6 weeks: Fibrosis slowly replaces granulation tissue

• 2 months: Dense fibrosis

Asthma

• Bronchiole lumen narrowing with mucus plug

• Exudate with nucleus and serous components

• Infiltration of eosinophils

• Hyperplasia and increased submucosal mucinous glands (basement membrane thicken) and smooth muscle (bronchial wall)

• Folded mucosa, thickened air walls

• Charcot-Leyden crystals

• Goblet cell hyperplasia

Lobar Pneumonia

• Inflammatory cell infiltrate in one lobule (Mainly neutrophils)

• Congested capillaries (dilated)

• Congestion of alveolar spaces filled with exudate:

  • Congestion: Bacteria (Serous exudate)

  • Red Hepatization: Fibrin, neutrophils, RBC

  • Grey Hepatization: Neutrophils, macrophage, digesting fibrin

  • Resolution: Cleared, enzymes digested exudate

• Edema of lungs

• Alveolar walls are thickened due to capillary congestion and edema

Pulmonary Tuberculosis

• Granulomatous inflammation (fibroblasts and mononuclear cells)

• Caseous necrosis (amorphous and eosinophilic)

• Langhan’s Giant Cell (horseshoe shape, macrophages fused together)

• Epitheloid histiocytes, lymphocytes and macrophages

• Tubercles with rounded outlines

• Ghonn’s focus/lesion = all of the above

Lung Adenocarcinoma

• Starts from peripheral of lungs

• Glandular formation and origin

• Mucin production, mucus glands stain positive

• Columnar cell proliferation

• Fibroblastic and inflammatory response

• Lepidic growth pattern (along alveolar septae)

Emphysema

• Wide and dilated alveolar spaces = formation of bullae

• Destruction of alveolar walls and septums due to proteolysis of elastic fibers

• Thick-walled capillaries

• Inflammatory cell infiltrate (neutrophilic)

Test for Renal Amyloidosis

• Congo Red staining – Red pigment deposited on amyloid deposits. Apple green under birefringence fluorescence.

• Thioflavine T – Fluorescence under UV light

Test for Hyaline Arteriosclerosis/Diabetic Glomerulosclerosis

• PAS staining of hyaline – Dark pink pigment

Test for Peptic Ulcer

• Urea Breath Test - Positive if H. pylori causes

Test for Meningitis

• CSF Analysis – culture for bacteria and check WBC count

Test for Pneumonia

• Blood tests for bacteria – S. pneumoniae, S. aureus

Test for Tuberculosis

• Sputum culture – Positive for M. tuberculosis

• Mantoux Test - Positive if there is a bump on skin