High-grade invasive urothelial carcinoma with focal plasmacytoid differentiation successfully treated by transurethral resection followed by chemoradiotherapy.

We report a case of high-grade invasive urothelial carcinoma with plasmacytoid differentiation of the urinary bladder. A 75-year-old woman was referred to our hospital because of macroscopic hematuria. Cystoscopy detected a solid pedunculated bladder tumor, and a transurethral resection of the bladder tumor (TUR-Bt) and the image findings showed pT1N0M0 bladder cancer. The histopathological examination revealed the coexistence of a large component of high-grade invasive urothelial carcinoma and a small component of plasmacytoid carcinoma. Following the TUR-Bt, external beam radiotherapy and chemotherapy with gemcitabine and nedaplatin were carried out. The bladder tumor has not recurred for 2 years after the TUR-Bt.