Malignancy in Bladder Diverticula

Bladder diverticula are associated with increased risk of malignancy due to chronic inflammation and urinary stasis. Malignancy in bladder diverticula occurs almost exclusively in adults with peak incidence between 65 yrs. and 75 yrs. The reported prevalence ranges from 0.8% to 10% of diverticula. The histologic types include urothelial carcinoma (70% to 80%) and squamous cell carcinoma (20% to 25%). Urothelial cancers arising in bladder diverticula are more likely to be high-grade and invasive as compared to non-diverticular malignancies. The image shows a non-invasive high-grade papillary urothelial carcinoma arising in a bladder diverticulum in an adult male. (discussion continues in the next image).