Papillary Adenoma of the Kidney
Differential Diagnosis
- Papillary renal cell carcinoma
- Clear cell renal cell carcinoma
- Carcinoma associated with end stage kidney disease
| Papillary Renal Cell Carcinoma | Renal Adenoma |
|---|---|
| >0.5 cm diameter | Papillary lesion ≤0.5 cm REQUIRED |
| May have any nuclear grade | Nuclear grade 1 or 2 REQUIRED |
| Conventional Clear Cell Renal Cell Carcinoma | Renal Adenoma |
|---|---|
| No size cutoff for clear cell tumors | Papillary lesion ≤0.5 cm, clear cells not permitted |
| May be high or low grade | Must be no higher than grade 2 |
| CK7, AMACR/racemase/P504S neg to focal | CK7, AMACR/racemase/P504S pos |
Two types of renal cell carcinoma are associated with end stage renal disease
- One is composed of cells with clear cytoplasm, the other of cells with high grade nuclear features
- Neither feature is permitted in renal adenomas
