Objective: To review our experience with nine cases of chromophobe renal cell carcinoma (ChRCC), classic type. The cytological descriptions of this entity are still rare, and information concerning the diagnostic value of cytology is needed.
Methods: Nine cases of ChRCC evaluated using fine needle aspiration (n = 6) or intraoperative scrape cytology (n = 3) were selected. Expression of vimentin was evaluated in four cases using immunocytochemistry, which was performed on alcohol-fixed material. In all cases a complete pathological study was available.
Results: The neoplastic cells were arranged mainly as single cells and small, discohesive, monolayered groups. A polymorphous cellular population was identified, with coexisting large, small and intermediate-sized cells. The large neoplastic cells showed clear, flocculent cytoplasm with small, eccentric nuclei and frequent binucleation. Dense, homogeneous cytoplasm was most commonly seen in smaller cells. Clear cytoplasmic spaces resembling perinuclear halos were frequently observed, best appreciated in cells with more dense cytoplasm. Binucleation and a marginal nuclear location were commonly seen. Necrosis, basement membrane or other stromal material were absent. Vimentin was not expressed in the four cases analysed. Precise cytological recognition was possible in the last five cases.
Conclusions: There is increasing evidence that a cytological diagnosis of ChRCC is possible. In our experience the histopathological features of ChRCC were well reflected in cytological samples, allowing specific recognition. In our cases the main differential diagnosis considered was clear cell carcinoma. Cytology can be especially helpful in the evaluation of intraoperative samples.