Collecting duct carcinoma: a rare malignancy.

A 45-years old man complained of hematuria, and subsequent examination and ultrasonography revealed a mass in the left kidney. Nephrectomy was performed and macroscopically an ill-defined pale-cream, irregular mass was identified which occupied predominantly the renal medulla. Histopathologic examination showed slit like tubular ducts lined by atypical cuboidal to polygonal cells and a marked desmoplastic stromal reaction. The diagnosis of collecting duct carcinoma was made. Patient is now doing well after 11 months of follow up.