CARCINOMA OF RENAL PELVIS
A man of 66 with pain in the left iliac fossa associated with vomiting and constipation was found to have an inoperable renal mass involving the sigmoid colon and retroperitoneal tissues. He died 4 days after laparotomy and the specimen was obtained at necropsy.
The kidney has been mounted to display the cut surface. An extensive tumour arising in the renal pelvis has resulted in a considerable degree of hydronephrosis due to infiltration and obstruction of the pelvi-ureteric junction. The tumour has penetrated the pelvis and infiltrated the adjacent connective tissue to form the lobular masses seen at the back of the specimen. Within the pelvis, the surface of the tumour has a mainly nodular appearance, however, in some areas, there is a fine papillary structure. Histological examination revealed a mixed squamous and papillary transitional cell carcinoma of the renal pelvis. The tumour had metastasized to the liver as a squamous cell carcinoma.
Small foci of squamous metaplasia are common in transitional cell carcinomas of urethelium. True mixed tumours are much less common and pure squamous cell carcinomas occur, but are rare.