Histopathologic features and clinical outcomes in 71 cases of bladder diverticula

Bladder diverticula often come to clinical attention when complications or malignancy occur, although limited information is available regarding histopathologic features and clinical outcomes.

To identify the morphologic findings, neoplastic subtypes, and clinical outcomes by reviewing all bladder diverticula that underwent pathologic sampling for primary diverticular processes at the Cleveland Clinic.

Hematoxylin-eosin slides from 71 cases of bladder diverticula were reviewed. Clinicopathologic features and patient outcomes were obtained from a retrospective review of patient records.

Patient ages ranged from 1 to 81 years (mean, 55 years), and the ratio of males to females was 68:3. Diverticular size ranged from 1 to 18 cm (mean, 5.3 cm) and often involved the lateral walls (38/71; 54%). Neoplastic changes were present in half of cases (36/71; 51%), including both noninvasive (16/36; 44%) and invasive (20/ 36; 56%) carcinoma. Of the invasive carcinomas, less-common subtypes included small cell carcinoma (n = 3), squamous cell carcinoma (n = 2), and adenocarcinoma (n = 1); 9 cases were pT1 (45%) and 11 cases were pT3 (55%). Follow-up for patients with benign findings demonstrated no subsequent neoplastic bladder disease. Patient follow-up for neoplastic diverticula (median, 27 months) demonstrated 4 cases of local recurrence and 3 cases of subsequent metastases. Of 9 patients with pT1 disease, only 1 patient (11%) developed subsequent metastases, whereas patients with pT3 disease demonstrated a higher rate of both local recurrence (3/11; 27%) and subsequent metastases (2/11; 18%).

Patients with invasive carcinoma in diverticula have an increased frequency of less-common bladder cancer subtypes, and those with pT3 disease are at increased risk for subsequent progression.