A case of mucus-producing papillary adenocarcinoma of the renal pelvis asso
ciated with multiple renal calculi in a 16-year-old male is reported. The m
ajority of the tumor cells contained large, round or cone-shaped, vimentin-
positive intracytoplasmic inclusions, which exhibited some morphological an
d immunohistochemical resemblance to inclusions found in malignant rhabdoid
tumor of the kidney. An intracytoplasmic accumulation of mucus was also no
ted in some tumor cells. The patient is free from recurrence and metastasis
after a nephrectomy.