Micropapillary bladder carcinoma is a rare variant of urothelial cancer. The clinical course is more aggressive than that of conventional urothelial cancer, but the optimal treatment for this malady has not been confirmed. There are few studies about micropapillary bladder cancer. So, we performed a clinico-pathololic review on 10 cases with micropapillary bladder cancer.

Between December 1994 and May 2003, of the 1,170 cases that had undergone transurethral resection of bladder tumor (TURB), we reviewed the pathology of 440 patients who had stage T1 or T2 disease. Of these, we identified 10 patients (2.3%) with micropapil-lary bladder cancer, and then the medical records of these 10 patients were reviewed retrospectively.

At the initial diagnosis, the average age was 66 years old (range: 48–79) and the male-to-female ratio was 4:1. After initially performing TURB, the pathological stages were T1G2 (1 case), T1G3 (5 cases) and T2G3 (4 cases), and the clinical stages were T1N0M0 (5 cases), T2N0M0 (2 cases), T3N0M0 (1 case), T2N2M0 (1 case) and T2N0M1 (1 case). Before the initial diagnosis, 75.0% (6/8 cases) of the urine cytology revealed malignancy. There were 4 cases of carcinoma-in-situ (CIS, 40%) and 5 cases of lympho-vascular invasion (50%). p53 gene mutation was reported in 66.7% (4/6 cases). Three quarters of the patients (6/8 cases) needed more aggressive treatments such as radical cystectomy or chemotherapy, with the exception of 2 patients who were lost to follow-up.

At the initial diagnosis, the patients with micropapillary bladder cancer had a high stage and grade. These patients were highly associated with poor prognostic factors such as CIS, lympho-vascular invasion and p53 gene mutation. Three quarters of the patients needed more aggressive treatments, so they need to undergo active surveillance and treatment before progression. (Korean J Urol 2007;48:910–914)