Collecting Duct Carcinoma of the Kidney

Collecting duct carcinoma (CDC) is a rare, highly aggressive malignant neoplasm that arises from the collecting duct epithelium of the kidney. It generally pursues a more aggressive course than conventional renal cell carcinoma. The average age is approximately 53 years. These are large tumors commonly located in medulla or central part of kidney with extension into perinephric fat and invasion into renal pelvis. Microscopically, they show combined tubulo-papillary, microcystic and solid growth pattern; cells are highly atypical with a basophilic or eosinophilic cytoplasm and polymorphic nuclei, often of the hobnail type. Stromal desmoplasia and dysplastic changes in the neighbouring medullary renal tubules are often associated. Their biologic behaviour is mostly aggressive with a high rate of local, lymphatic and haematogenous spread at the times of diagnosis and a poor long-term prognosis.