[1075] Histopathological and Clinical Characterization of Intradiverticular Carcinoma in Urinary Bladder

Hua Zhong, Gissou Azabdaftari, Bo Xu. Roswell Park Cancer Institute, Buffalo, NY

Background: Intradiverticular bladder carcinoma accounts for only 1.5% of all carcinomas arising in the urinary bladder. Its histopathologic features and clinical outcomes are not well characterized due to its rarity. In this study, we analyze a relative large series of intradiverticular carcinoma of bladder with main focus on its histopathological features and clinical outcome.
Design: We identified 21 cases of intradiverticular carcinomas of urinary bladder diagnosed at our institution between 1995 and 2011. Hematoxylin-eosin stained slides were reviewed. Tumor subtype and staging was based on WHO classification of bladder cancer and AJCC Cancer Staging Manual. Clinicopathologic features and patient outcomes were obtained from a retrospective review of patient records.
Results: All patients are Caucasian. Patient's mean age was 68 years (42 to 85) with male to female ratio 20:1. Mean tumor size was 2.1 cm (0.5 to 5.5). 75% tumor involved the lateral walls. Histologically, 8 cases (38%) were non-invasive papillary urothelial carcinoma (UCC), 10 cases (48%) were infiltrating UCC and 3 cases (14%) were small cell carcinoma (SCC). All infiltrating tumors and 5 non-invasive ones were high grade carcinomas. Two SCCs had coexisting high grade infiltrating UCC. Urothelial carcinoma in situ was present in two infiltrating urothelial carcinomas and all three SCCs. Among invasive carcinoma, 9 cases were T1 and 4 cases were T3/4 tumors. More than half (57%) cases showed hypertrophic layer of masculari mucosa. Synchronous extradiverticular urothelial carcinomas were observed in 5 out of 8 cases (63%) of non-invasive intradiverticular UCC and in 2 out of 10 cases (20%) of infiltrating UCC. Patient follow up (median 30 months) reveal that disease free time was similar between non-invasive and infiltrating UCC (21.5 and 27.5 months, respectively). However, the three SCC cases had much shorter disease free time (1.7 months). Both diseases free time and overall survival was significantly shorter in higher stage (stages III/IV) compared to that of lower stage carcinomas (10.8 and 17.2 months vs 26 and 30.2 months).
Conclusions: Non-invasive intradiverticular bladder carcinomas are more likely to have coexisting synchronous extradiverticular lesions. Hypertrophic mascularis mucosa is a common histological feature of intradiverticular bladder carcinoma, which can pose challenge in tumor staging. SCC recurs shortly after the procedure comparing to its UCC counterpart. Tumor stage remains a key prognostic factor in intradiverticular bladder carcinoma as in the conventional ones.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 145, Wednesday Afternoon


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