[921] Histopathologic and Clinical Features of Vesical Diverticula

Max X Kong, Xiangrong Zhao, Emil Kheterpal, Peng Lee, Samir Taneja, Jonathan Melamed, Fang-Ming Deng. NYU Langone Medical Center, New York, NY; New York University School of Medicine, New York, NY

Background: Urinary bladder diverticulum, an uncommon bladder disorder, only catches clinical attention when complicated with inflammation, calculi or malignancy. Limited information is known about the histopathologic and clinical features of bladder diverticulum.
Design: We retrieved 94 cases of bladder diverticula from the archives over the past 13.5 years (1998 to 2011). Slides were reviewed to identify pathologic findings. Retrospective clinical follow-up was obtained for all cases.
Results: Patients' ages ranged from 1 to 89 (66 ± 18) years. The ratio of male to female was 90:4. Sixty-eight of 94 (72%) patients were Caucasian, which approximated 33% in local general population. The documented diverticular sizes ranged from 0.4 to 11.4 (4.4 ± 2.8) cm. Diverticula most often involved the lateral wall (27%), followed by the posteriolateral (25%) and posterior (19%) walls of the bladder.
Sixty-six of 94 (70%) cases showed benign processes including: inflammation (48); squamous (5) or intestinal (1) metaplasia; nephrogenic adenoma (3); low to moderate grade dysplasia (2); reactive atypia (2); focal papillary hyperplasia (2); polypoid cystitis (2) and cystitis cystica (1). Twenty-eight cases (30%) showed primary carcinomas arising from the diverticula, of which 25 cases are of urothelial carcinoma and 3 cases of rare type carcinoma (table 1).

Table 1. Histologic findings in 28 neoplastic vesical diverticula

Histologic type	Urothelial Ca	25 (89%)
	Squamous cell Ca	2 (7%)
	Adenocarcinoma	1 (4%)
Grade	Low grade	6 (21%)
	High grade	22 (79%)
Pathologic stage	Ta	7 (25%)
	Tis	4 (15%)
	T1	11 (39%)
	T3	6 (21%)

Patient follow-up for neoplastic diverticula (1-108 months) showed none of the patients died from progression of vesical carcinoma. Fifteen (54%) cases had concurrent or subsequent urothelial carcinoma in non-diverticular bladder. Four cases with subsequent extra-diverticular urothelial carcinoma showed progression, with their pathology up-staging.
Conclusions: This study represents the largest case series up to date on surgically resected bladder diverticula. Inflammation, metaplasia and dysplasia are commonly seen in vesical diverticula. Patients with bladder diverticula appear to have significantly higher risk for development of urothelial carcinoma, which can occur synchronously or precede carcinoma of the non-diverticular bladder. Of note, in comparison to their non-diverticulum-associated counterparts, a significantly higher percentage of diverticulum-associated bladder carcinoma are high grade and invasive and may have a more adverse outcome.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 125, Monday Morning