Ureteral pseudodiverticula: frequent association with uroepithelial malignancy

Ureteral pseudodiverticula are tiny outpouchings usually seen as incidental findings on retrograde urography during routine work-up for common urinary tract disorders. We report 37 patients with ureteral pseudodiverticula, of whom 17 (46%) had associated uroepithelial malignancy. Ureteral pseudodiverticula were diagnosed in all patients on excretory or retrograde urography as an incidental finding during evaluation for a variety of urologic symptoms and signs. All patients were assessed with urinalysis, urine culture, cystoscopy, and when indicated, ureteroscopy. Diagnosis of transitional cell carcinoma was made by surgery or endoscopic biopsy in 16 patients and squamous cell carcinoma in one. In nine patients with radiographs showing ureteral pseudodiverticula and a urinary tract filling defect (usually in the bladder), 78% of the cases were proved malignant. In six patients with ureteral pseudodiverticula and a stricture in the ureter or renal collecting system, 67% of the cases were proved malignant. Of the patients with tumor, 53% had a single ureteral pseudodiverticulum. In two cases, the pseudodiverticula antedated the diagnosis of malignancy by 2 and 4 years, respectively. Our experience suggests that the association between ureteral pseudodiverticula and uroepithelial malignancy may be more common than previously assumed, approaching 50%. Even a single ureteral pseudodiverticulum should be regarded as a serious marker for potential malignancy, antedating cancer by 2-10 years, and such patients should be closely followed up. The coexistence of ureteral pseudodiverticula and a stricture or filling defect in the urinary tract is highly suggestive that a tumor is present.