Bellini duct carcinoma: a rare variant of renal cell carcinoma.

Bellini Duct Carcinoma (BDC) or collecting duct carcinoma is a rare but very aggressive renal neoplasm which originates from the epithelium of the ducts of Bellini in the distal tubule. This tumour often occurs in a young population and has a bad prognosis. Histomorphological differentiation from the more common renal cell carcinoma of the proximal tubuli is difficult. Immunohistochemic and cytogenetic characterisation can lead to the correct diagnosis.