[A case of inflammatory pseudotumor of the urinary bladder that was difficult to differentiate from sarcoma]

On September 25th, 2003, a 39-year-old man complained of asymptomatic gross hematuria. He was admitted to a nearby hospital and evaluated. Cystoscopy revealed a non-papillary broad base tumor in the anterior wall of the bladder. On October 2nd, a TUR-Bt was performed. The pathological diagnosis was difficult to determine because mitosis and nuclear pleomorphism were apparent. He next came to our hospital for further evaluation. We diagnosed his condition as an inflammatory pseudotumor of the bladder because fibroblasts and inflammatory cells had increased; however, we did not see abnormal nuclear mitosis or severe pleomorphism. Although we did not perform a complete TUR-Bt, the mass regressed spontaneously and did not reoccur. The presence of mitosis and mild nuclear pleomorphisms make certain cases difficult to diagnose as inflammatory pseudotumors. Inflammatory pseudotumors are generally considered benign, and some cases regress spontaneously. It is important that we are able to identify and characterize these pseudotumors in order to avoid more invasive surgeries whenever possible.