variant 1 - doc 2

calcification definition, types, histochemical identification

🟩 1. Calcification

Definition:

Deposition of calcium salts (mainly calcium phosphate/carbonate) in tissues → hardening.

Types:

Dystrophic calcification

→ deposition in necrotic / degenerated tissues

→ occurs with normal serum calcium

Metastatic calcification

→ deposition in normal tissues

→ due to hypercalcaemia (↑ PTH, ↓ calcitonin, bone resorption, vit D excess)

Calculi formation

→ stone formation in ducts/cavities (e.g. kidney, gallbladder)

Histochemical identification:

Von Kossa stain → calcium deposits stain black (VK)

H&E → basophilic granular deposits

🟩 2. Metaplasia

🟩 2. Metaplasia

Definition:

Reversible change where one mature cell type is replaced by another due to chronic stress/irritation.

Types: - MEMSCOC … MESENCHYMAL + EPITHELIAL (MESEP)

Epithelial metaplasia

Mesenchymal metaplasia

Morphology: COCS - CARTI COLUMNA OSSEOUS, SQUAMOUS

Squamous metaplasia

Columnar metaplasia

Osseous metaplasia

Cartilaginous metaplasia

🟩 3. Apoptosis vs Necrosis Apoptosis

Programmed, energy-dependent cell death of single cells.

Morphology:

• cell shrinkage

• chromatin condensation

• membrane blebbing

• apoptotic bodies

• phagocytosis by macrophages

• NO inflammation

Features:

• ATP-dependent

• organelles preserved

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Necrosis

Uncontrolled pathological cell death with enzyme digestion.

Morphology:

• cell swelling

• membrane rupture

• enzyme leakage

• inflammation present

• multiple adjacent cells affected

• MACROPHAGE PHAGOCUTISE

🟩 4. Chronic vs Acute Inflammation Chronic inflammation

🟩 4. Chronic vs Acute Inflammation Chronic inflammation

• persistent inflammatory response + tissue repair

Cells:

• macrophages

• epithelioid cells

• giant cells (fused epitoloid)

• T & B lymphocytes

• plasma cells

• fibroblasts → fibrosis

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Acute inflammation

Main cells:

NEL

• neutrophils (primary)

• eosinophils (allergy/parasites)

Key features:

• VIE

• vasodilation

• increased vascular permeability

• exudate formation

🟩 5. Physical carcinogenesis

🟩 5. Physical carcinogenesis

Definition:
Cancer caused by physical agents (radiation).

Types:

• UV radiation → skin cancer (BCC, SCC, melanoma risk)

• Ionising radiation (X-rays, gamma rays)
  → DNA damage → mutations

papilloma

🟩 6. Papilloma

Definition: - BET FF FVC
Benign epithelial tumour forming finger-like projections with fibrovascular cores. - FVC

Features:

WEDE - ALL SKIN LIKE STUFF - ON OUTSIDE

• exophytic growth

• derived from epithelium

• wart-like lesion

Common sites:
skin, oral cavity, laryn

metastasis

🟩 7. Metastasis

Definition:
Spread of malignant tumour cells from primary site to distant organs.

Routes:

• lymphatic

• hematogenous

Steps:

II CEC

1. invasion

2. intravasation

3. circulation

4. extravasation

5. colonisation

Key point:
Only malignant tumours metastasise (except rare exceptions like gliomas, basal cell carcinoma rarely)

protein accumulation

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🟩 8. Protein accumulation

Definition:
Abnormal intracellular or extracellular protein deposition.

Examples:

• Mallory bodies (mallory failed cyto cause she was getting her hair done)
  → alcoholic liver disease
  → cytokeratin aggregates in hepatocytes

• Russell bodies
  → in plasma cells (rounded pink inclusions)
  → caused by immunoglobulin accumulation

• Lewy bodies
  → in neurons
  → causes parkinson’s disease

• α1-antitrypsin deficiency
  → protein accumulation in hepatocytes

Tuberculoma structure

🟩 9. Tuberculoma

Definition:
Localized granulomatous lesion caused by Mycobacterium tuberculosis.

Structure:

• central caseous necrosis (“cheese-like”)

• surrounded by epithelioid cells

• Langhans giant cells

• lymphocytes

• fibrous capsule forms around the whole thing

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PE + OUTCOMES!!

🟩 10. Pulmonary embolism

Definition:
Blockage of pulmonary arteries by embolus.

Origin:

• most commonly deep veins of lower limbs/pelvis

Types:

• thromboembolus (most common)

• fat embolus

• air embolus

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Outcomes:

• pulmonary infarction (hemorrhagic infarct)

• acute right heart failure → sudden death (massive PE)

• pulmonary hypertension → chronic cor pulmonale