Core Concepts
Histopathology
Microscopic examination of tissue to diagnose disease, especially cancer.
Cytopathology
The study of cells for disease diagnosis, including Pap smears and fine needle aspirates.
Autopsy
Post-mortem examination to determine cause of death and study disease processes.
Immunohistochemistry
Using antibodies to detect specific proteins in tissue sections, helping identify tumor types.
Molecular Pathology
Study of disease at the molecular level, including genetic mutations and biomarkers.
Worked Examples & Applications
TNM Staging System: T (Tumor size): T1-T4. N (Node involvement): N0-N3. M (Metastasis): M0-M1. Example: T2N1M0 = tumor 3-5 cm, 1-3 positive lymph nodes, no distant metastasis.
Pap Smear Classification: Normal → ASC-US (atypical squamous cells of undetermined significance) → LSIL (low-grade squamous intraepithelial lesion) → HSIL (high-grade) → Invasive carcinoma.
Practice Questions
Q: What is the difference between histopathology and cytopathology? A: Histopathology examines tissue sections (biopsies). Cytopathology examines individual cells (smears, aspirates).
Q: What does TNM stand for? A: Tumor size, Node involvement, Metastasis — the standard cancer staging system.