(P) HT Lec L1-L3 I

https://docs.google.com/document/d/1zZEb9YCQYeRTM9dbFum7feJjsHZRVZ7_O-Ip5BtMu0k/edit?usp=sharing

Lesion

Key Histopathological Terminology

Any structural tissue change caused by disease or injury.

Neoplasm

Key Histopathological Terminology

Abnormal, uncoordinated new growth of tissue forming a tumor.

Benign

Key Histopathological Terminology

Localized, slow-growing, non-invasive tumor with well-differentiated cells.

Malignant

Key Histopathological Terminology

Cancerous, rapidly growing tumor capable of local invasion and distant metastasis.

Hyperplasia

Key Histopathological Terminology

Increase in the total number of cells in a tissue or organ.

Hypertrophy

Key Histopathological Terminology

Increase in individual cell size, resulting in overall organ enlargement.

Atrophy

Key Histopathological Terminology

Decrease in individual cell size, leading to tissue or organ shrinkage.

Metaplasia

Key Histopathological Terminology

Reversible replacement of one mature cell type by another mature cell type.

Dysplasia

Key Histopathological Terminology

Disordered growth and maturation of cells with nuclear atypia; considered a premalignant lesion.

Autolysis

Key Histopathological Terminology

Post-mortem decomposition driven by intracellular enzymatic self-digestion; accelerated by heat and retarded by cold.

Putrefaction

Key Histopathological Terminology

Post-mortem decomposition driven by intestinal bacteria; produces foul odor, gas, and tissue discoloration.

Hematoxylin & Eosin (H&E)

Diagnostic Staining Evolution

Primary routine stain; nuclear details (blue/purple) and cytoplasm/extracellular matrix (pink).

Periodic Acid-Schiff (PAS)

Diagnostic Staining Evolution

Glycogen, fungal elements, and basement membranes.

Masson's Trichrome

Diagnostic Staining Evolution

Connective tissue fibers (collagen vs. muscle).

Silver Stains

Diagnostic Staining Evolution

Reticular fibers and specific microorganisms.

Ziehl-Neelsen Stain

Diagnostic Staining Evolution

Acid-fast bacilli (e.g., Mycobacterium tuberculosis).

Immunohistochemistry (IHC)

Diagnostic Staining Evolution

Uses labeled antibodies to target specific cellular proteins; critical for tumor classification.

Molecular Techniques

Diagnostic Staining Evolution

In situ hybridization (ISH) and PCR-based assays for genetic profiling.

Incisional Biopsy

Specimen Categories and Biopsy Modalities

Diagnostic removal of only a representative portion of a lesion.

Excisional Biopsy

Specimen Categories and Biopsy Modalities

Therapeutic/diagnostic removal of the entire lesion along with surrounding borders (e.g., melanoma).

Punch Biopsy

Specimen Categories and Biopsy Modalities

Cylindrical core blade that pierces epidermis, dermis, and superficial subcutis (common for skin lesions).

Shave Biopsy

Specimen Categories and Biopsy Modalities

Epidermal and superficial dermal removal via horizontal blade shaving.

Fine Needle Aspiration (FNA)

Specimen Categories and Biopsy Modalities

Uses a thin-gauge needle to aspirate individual cells/fluid from suspicious masses (e.g., thyroid, breast).

Core Needle Biopsy

Specimen Categories and Biopsy Modalities

Uses a large-bore hollow needle with a specialized tip to extract a intact tissue cylinder.

Wire-Localized / Stereotactic

Specimen Categories and Biopsy Modalities

Radiographically or MRI/mammography-guided needle/wire localization for non-palpable lesions prior to excision.

Endoscopic Biopsy

Specimen Categories and Biopsy Modalities

Fiberoptic scope sampling via natural orifices or small incisions (e.g., GI endoscopy, cystoscopy, bronchoscopy).

Surgical Resections

Specimen Categories and Biopsy Modalities

Large tissue or organ specimens (e.g., appendectomy, cholecystectomy, hysterectomy, mastectomy) requiring detailed gross description.

Autopsy Specimens

Specimen Categories and Biopsy Modalities

Post-mortem tissues categorized into Clinical/Hospital (disease progression/cause of death) or Medicolegal/Forensic (sudden, suspicious, or violent death).

Cytology Specimens

Specimen Categories and Biopsy Modalities

Microscopic examination of individual cell smears (e.g., Pap smear, sputum, urine, pleural/peritoneal fluids).