Collecting duct carcinoma mixed with common renal cell carcinoma: analysis of morphological characteristics using lectin histochemistry.

Recently, cases of collecting duct carcinoma have been reported which were thought to have arisen from the renal collecting ducts or distal tubuli. We present here a rare case of collecting duct carcinoma mixed with common (conventional) renal cell carcinoma. A 51-year-old man underwent right nephrectomy under the diagnosis of renal tumor. Histochemically, markers for the collecting ducts/distal tubuli, such as peanut agglutinin (PNA) and soybean agglutinin (SBA), were identified in the collecting duct carcinoma as well as on several luminar surfaces of the common renal cell carcinoma. Based on the results of histological, histochemical and chromosomal examinations, we speculated on the histogenesis of this collecting duct carcinoma.