[Squamous cell carcinoma of the renal pelvis associated with giant hydronephrosis--report of an autopsy case].

An autopsy case of squamous cell carcinoma of the renal pelvis associated with giant hydronephrosis, which is the fourth case in the Japanese literature, is reported. A 37-year-old man, who had been found to have a left abdominal mass was admitted because of dyspnea and lumbar pain. At autopsy the left kidney contained 2,550 ml of turbid yellowish fluid in the pelvis, with a tumor protruding from the cystic wall. Histologically, the tumor was mostly composed of squamous cell carcinoma, which showed keratinization and pearl formation, with focal transitional cell carcinoma and squamous metaplasia. The ureteropelvic junction was slightly obstructed by muscular hypertrophy and fibrosis.