Enteric type adenocarcinoma of the upper tract urothelium associated with ectopic ureter and renal dysplasia: an oncological rationale for complete extirpation of this aberrant developmental anomaly.

PURPOSE: Intestinal metaplasia of the urothelium occurs in chronically irritated retained urinary segments and can progress to enteric adenocarcinoma. We present a unique clinical experience with a closed segment ureter from a dysplastic kidney draining ectopically into the seminal vesicle with malignant degeneration to enteric adenocarcinoma. The implications of this experience for management of this anomaly are discussed.

MATERIALS AND METHODS: Clinical and pathological data were assimilated with the urological and pathological literature.

RESULTS: Pathological examination revealed replacement of the urothelium of the renal pelvis and ureter with intestinal type metaplasia and multifocal transformation to mucinous (tubular villose) poorly differentiated adenocarcinoma. Preoperative computerized tomography failed to identify the extensive malignancy.

CONCLUSIONS: Our experience demonstrates that this anomaly is another scenario in which closed spaced nonfunctional urothelium can undergo malignant degeneration. Since monitoring such units for tumor progression does not seem to be possible presently, conservative treatment appears hazardous. This new recognition of the risk of malignant metaplastic degeneration is an additional rationale to consider complete extirpation of these lesions as the most appropriate treatment in young men.