Bladder cancer: Analysis of the 2004 WHO classification in conjunction with pathological and geographic variables

Objectives: Bladder cancer (BCA) is aworldwide disease and shows a wide range of geographical variation. The aim of this study is to analyze the prevalence of schistosomal and non-schistosomal associated BCA as well as compare our findings with the 2004 WHO consensus classification of urothelial neoplasms and with other publications. Patients and methods: The archival materials of 180 urinary bladder specimens were collected from Department of Pathology, King Abdul-Aziz University Hospital (KAUH), Jeddah, Western region, Saudi Arabia. The regional prevalence of this cancer was identified and studied, and a comparison between schistosomal and non-schistosomal associated BCA was made. Additionally, the study revised and classified these neoplasms according to the most recent 2004 WHO classification of urothelial neoplasms. The type of mural invasion either muscularis mucosae (MM) or muscularis propria (MP), other associated lesions as carcinoma in situ (CIS) as well as, metaplasia and schistosomal infestation were assessed. Results: Urothelial cell neoplasms (UCN) comprised 161 cases (89.4%), squamous cell carcinoma (SCC) represented 12 cases (6.7%), adenocarcinoma 5 cases (2.8%), and sarcomatoid carcinoma detected in 2 cases (1.1%). Among all these cases schistosomal associated BCA represented 13 cases (7.2%), while the remaining 167 cases (92.8%) were non-schistosomal associated BCA. In the former category, 11 cases (6.1%) were squamous cell carcinoma and 2 (1.1%) urothelial cell carcinoma (UCC) whereas, non-schistosomal associated cancer that included UCN, SCC, adenocarcinoma, and sarcomatoid carcinoma found in 159, one case, 5, and 2 cases. Invasion of muscularis propria was detected in 30 cases (16.7%) and muscularis mucosae invasion in 45 cases (25%). Conclusion: According to WHO classification of urothelial neoplasms accurate categorization of BCA is very important for both diagnostic and therapeutic values.