Extravasation in ureteral tumours.

Extravasation of contrast medium following retrograde pyelography may occur when excessive pressure is used during injection of the contrast medium, direct trauma during manipulation of the ureteral catheter or pre-existing ureteral disease. Extravasation of contrast medium occurring in a ureteral tumour is rare. A case where extravasation of contrast medium was observed during retrograde pyelography due to extensive invasion of the ureter by a primary ureteral tumour is reported.