Systemic Pathology: Organ-Based Non-Neoplastic Disease
Systemic Pathology tests organ-based non-neoplastic disease: atherosclerosis and ischemia, obstructive and restrictive lung disease, pneumonia, peptic ulcer disease, cirrhosis, glomerular disease and diabetes. The exam rewards linking pathogenesis to morphology and to a clinical syndrome.
Core rules
- Atherosclerosis begins with endothelial injury, LDL retention and oxidation, monocyte recruitment, foam-cell formation and fibrous-cap remodeling. Plaque rupture exposes thrombogenic core.
- Myocardial infarction evolves from coagulation necrosis to neutrophilic infiltration, macrophage cleanup and granulation tissue; complications include arrhythmia, rupture, aneurysm and mural thrombus.
- COPD shows airflow limitation with emphysema and chronic bronchitis; asthma shows reversible bronchospasm with eosinophils and basement-membrane thickening.
- Cirrhosis is diffuse nodular regeneration with bridging fibrosis; it causes portal hypertension, ascites, varices and hepatocellular carcinoma risk.
- Nephrotic syndrome has heavy proteinuria, hypoalbuminemia, edema and hyperlipidemia; nephritic syndrome has hematuria, hypertension and oliguria.
Worked example
A 45-year-old woman has 5 g/day proteinuria, edema and normal renal function. Biopsy shows diffuse glomerular basement-membrane thickening, granular IgG and C3, and subepithelial deposits with spike-and-dome silver staining. This is membranous nephropathy, a nephrotic pattern. The subepithelial location explains proteinuria without prominent inflammation. Secondary causes such as hepatitis B, lupus and malignancy should be excluded.
Traps
Do not call all glomerular disease nephritic. Transudate has low protein and low cells; exudate has high protein and cells. Cirrhosis requires fibrosis plus nodules, not fibrosis alone. Emphysema destroys alveolar walls; chronic bronchitis is defined clinically by chronic productive cough.