Urothelial tumours of the urinary bladder: a histopathological study of cystoscopic biopsies.

Introduction: Bladder tumours constitute one of the most common urological conditions. Urothelial (transitional cell) carcinoma accounts for 90% of all primary tumours of the bladder. These tumours are an important cause of morbidity and mortality. The objective of this study was to present the histopathological patterns of urothelial tumours and to determine the grade and stage of these tumours.

Methods: This is a 3 year descriptive study of urothelial tumours carried out in the Department of Pathology, Patan Academy of Health Sciences (PAHS), Lalitpur, Nepal. Data of all cystoscopic biopsies collected during this period were analyzed.

Results: Of the 83 urinary bladder tumours, 81 (97.59%) cases were urothelial (transitional cell) tumours. Transitional cell carcinoma (TCC) was the most common bladder tumour which was seen in 67 (80.72%) cases. Thirty two (47.76%) cases of TCC were low grade while 35 (52.24%) were high grade. Forty three (64.18%) cases of TCC were superficial or in early stage (pTa and pT1) while 24 (35.82%) showed muscle invasion.

Conclusions: Transitional cell carcinoma was the most common bladder cancer. Most of these tumours were high grade. A large percentage of high grade carcinomas presented with muscle invasion. Pathological grade and muscle invasion are the most valuable prognostic predictors of survival. The importance of including smooth muscle in the biopsy specimens needs to be emphasized.