Adenocarcinoma of the renal pelvis with vimentin-positive intracytoplasmic inclusions.

A case of mucus-producing papillary adenocarcinoma of the renal pelvis associated with multiple renal calculi in a 16-year-old male is reported. The majority of the tumor cells contained large, round or cone-shaped, vimentin-positive intracytoplasmic inclusions, which exhibited some morphological and immunohistochemical resemblance to inclusions found in malignant rhabdoid tumor of the kidney. An intracytoplasmic accumulation of mucus was also noted in some tumor cells. The patient is free from recurrence and metastasis after a nephrectomy.