Clear cell neoplasms of the urinary tract and male reproductive system.

Herein is a review of clear cell neoplasms of selected sites in the urinary tract and male reproductive system, including the kidney, the urinary bladder, testis, epididymis, and prostate. Clear cell cytoplasmic alteration in neoplasms at these sites is a relatively common light microscopic finding. Examples of such neoplasms with clear cell change include the clear cell type of renal cell carcinoma, clear cell adenocarcinoma of urethra and bladder, the classic type of seminoma, papillary cystadenoma of the epididymis, and well-differentiated adenocarcinoma of the prostate. Of importance, numerous non-neoplastic benign entities may also manifest cleared cytoplasm and therefore are presented in the differential in this review. Indeed, knowledge of the neoplastic and non-neoplastic entities displaying clear cell change at each anatomic site should enable the surgical pathologist to approach the differential diagnosis of these conditions in a more logical and rigorous fashion.