Chromophobe Renal Cell Carcinoma

Abstract

Chromophobe renal cell carcinoma (ChRCC) makes up approximately 5% of all cases of renal cell carcinoma (RCC) [1]. First described in 1985, this rare subtype of RCC was originally thought to arise from the intercalated cells of the collecting ducts. This disease is challenging to diagnose, and on biopsy, this malignancy can share histologic similarities with benign oncocytomas using conventional evaluation or even be misclassified as the more common clear-cell RCC [2–4]. Therefore, careful histologic attention is needed to appropriately capture these cases. Histologically, two variants of ChRCC are recognized: classic ChRCC and an eosinophilic variant [5]. The classic type is more common and is characterized by large cells with pale “chromophobe” cytoplasm and a perinuclear halo or clearing. On the other hand, the tumor cells in the eosinophilic variant display a dense eosinophilic cytoplasm and perinuclear halos (Fig. 4.1).