Carcinoma arising in urinary bladder diverticula: imaging findings in six patients.

Objective: Carcinoma arising within urinary bladder diverticula has a poorer prognosis than do neoplasms that originate within the main bladder lumen as a result of early transmural tumor infiltration. Imaging plays an important role in diagnosing and staging the disease. We describe the radiologic findings in six patients with pathologically proved diverticular carcinomas.

Materials And Methods: We reviewed the records of six patients who had radiologic examinations and surgically confirmed vesical diverticular carcinomas. The examinations included excretory urography in three patients, cystography in three patients, CT in five patients, and MR imaging in one patient. All patients had hematuria. Five patients had transitional cell carcinoma, and one patient had squamous cell carcinoma.

Results: Three of the tumors manifested as an intraluminal filling defect within a bladder diverticulum on excretory urograms or cystograms. In one patient, CT scans showed a concentric soft-tissue tumor in a diverticular neck. Correlative cystograms showed only smooth narrowing in this area. CT and MR imaging showed a tumor within a large diverticulum, which was not visualized on cystograms because of obstruction at the diverticular orifice.

Conclusion: Imaging plays an important role in identifying bladder diverticula as a potential site of occult neoplasm.