Renal Cell Carcinoma (RCC)
Renal cell carcinoma is the most common primary renal malignancy in adults, originating from the proximal renal tubular epithelium. It is known as the “internist’s tumor” because of its diverse paraneoplastic syndromes.
1. Classic Clinical Presentation
The classic triad of RCC is hematuria, flank pain, and a palpable mass. Note: This triad is present in < 10% of cases and often indicates advanced disease.
2. Paraneoplastic Syndromes
RCC is famous for producing various hormones, leading to specific systemic effects:
- Erythropoietin: Polycythemia.
- PTHrP: Hypercalcemia.
- Renin: Hypertension.
- ACTH: Cushing syndrome.
3. Pathological Patterns & Associations
| Pattern | Key Features |
|---|---|
| Clear Cell RCC | Most common subtype; often associated with VHL gene mutation (3p deletion). |
| Risk Factors | Smoking, obesity, hypertension, and exposure to cadmium or asbestos. |
4. Exam Must-Knows
- Extension: RCC has a unique tendency to invade the renal vein and grow as a tumor thrombus into the inferior vena cava (IVC).
- Von Hippel-Lindau (VHL): Increased risk for clear cell RCC, hemangioblastomas of the CNS/retina, and pheochromocytomas.
Pathology Board Hint: For test questions, if you see a patient with hematuria and a paraneoplastic syndrome (especially erythrocytosis or hypercalcemia), suspect RCC. Remember that Clear Cell RCC is the most common form and is strongly linked to VHL mutations.