Renal cell carcinoma in polycystic kidneys: case report and review of literature.

A case of polycystic kidneys associated with a sarcomatoid variant of renal cell carcinoma is reported. The patient presented with hilar lymphadenopathy, para-aortic lymph node enlargement with an abnormal lymphangiogram and splenomegaly. Biopsy of the hilar lymph node, para-aortic lymph node and spleen showed reactive hyperplasia only but biopsy of the left kidney, liver and mesentery revealed poorly differentiated renal cell carcinoma with sarcomatous changes.