Pathology
Core framework
Pathology questions ask you to connect mechanism to morphology to clinical consequence. Master cell injury and death (necrosis versus apoptosis), acute and chronic inflammation, wound healing, hemodynamic disorders (thrombosis, embolism, infarction, shock), neoplasia (benign versus malignant, grading and staging, tumor markers, metastasis routes), and the major systemic disease patterns by organ.
Concepts you must own
The morphological types of necrosis and the tissues they affect. The cells and mediators of acute versus chronic inflammation and granuloma formation. The Virchow triad. The difference between grading and staging. The pathways of spread for common tumors.
Traps
- Metaplasia versus dysplasia versus neoplasia: metaplasia is adaptive and reversible; dysplasia is disordered but not necessarily invasive.
- Grading versus staging: grade is differentiation; stage is anatomical extent and carries the stronger prognosis.
- Necrosis type: coagulative versus liquefactive versus caseous versus fat versus fibrinoid each has a characteristic setting.
Worked rule of thumb
When a stem describes a mass, decide benign versus malignant from invasion, metastasis, and cellular atypia, then decide grade from differentiation and stage from extent. If asked for prognosis, stage usually wins. If asked for aggressiveness at a single site, grade is the better answer.