FNAC Diagnosis of eosinophilic variant of chromophobe renal cell carcinoma – A challenge for cytopathologists

Abstract

Chromophobe Renal Cell Carcinoma (ChRCC) is a rare distinct subtype of Renal cell carcinoma. It arises from intercalated cells of the renal cortex. The cytomorphological features of ChRCC show significant overlap with Clear cell Renal Cell Carcinoma (CCRCC) and Oncocytoma. The prognosis of ChRCC is intermediate between benign Renal Oncocytoma and the relatively aggressive CCRCC. Hence, a correct pre or intra-operative cytodiagnosis helps in deciding the extent of surgery. We report a case of eosinophilic variant of ChRCC in a 70 years female, diagnosed on Fine Needle Aspiration Cytology (FNAC).The Immunocytochemistry (ICC), histology and Immunohistochemistry confirmed the diagnosis of ChRCC. Diagnosing ChRCC; especially its eosinophilic variant on FNAC is very challenging. Prominent cellular heterogeneity, pleomorphism, perinuclear halos and binucleation are important diagnostic clues for cytodiagnosis of ChRCC. In difficult cases, ICC helps in confirming the diagnosis.