Metastatic Micropapillary Variant of the Urinary Bladder : Progression from Low Grade Non-Muscle Invasive Bladder Carcinoma

We report a case of metastatic micropapillary variant of the bladder that progressed from low grade non-muscle invasive bladder carcinoma. Lung, para-aortic and pelvic lymph nodes metastatic lesions were found in a 62-year-old woman, who had been followed due to non-muscle invasive bladder carcinoma. The bladder wall was found to be thick by computerized tomography (CT). She had had transurethral resection of bladder tumor (TURBT) at 60 and 61 years old, followed by intravesical therarubicin and bacille Calmette-Guérin therapy, respectively. Both TURBT specimens showed low grade, non-muscle invasive urothelial carcinoma. The thickened bladder wall was resected transurethrally and the pathological examination revealed that the recurrent tumor was entirely composed of micropapillary variant component. There must have been tiny lesions of a micro papillary variant component after the second TURBT. Several reports suggest that intravesical BCG therapy was ineffective for micropapillary variant. So the UC component was substituted for micropapillary component.