A 49-year-old woman presenting with hepatoid adenocarcinoma of the urinary bladder: a case report

INTRODUCTION: Adenocarcinomas represent less than 2 percent of all urothelial neoplasms. Hepatoid adenocarcinoma is rare in the urinary bladder. Pathological diagnosis is based on a combination of histological features resembling hepatocellular carcinoma and positive immunostaining for α-fetoprotein. CASE PRESENTATION: We report a case of hepatoid adenocarcinoma of the urinary bladder. A 49-year-old Japanese woman underwent a total mastectomy, and post-operatively abdominal computed tomography revealed a tumor of the urinary bladder. Trans-urethral resection of the bladder tumor was performed, and pathological examination revealed a hepatoid adenocarcinoma of the urinary bladder. Our patient has had no evidence of recurrence 20 months after surgery to remove the tumor. CONCLUSIONS: Hepatoid adenocarcinoma seems to be an aggressive malignant neoplasm that is rare in the urinary bladder. This case report is only the ninth case of hepatoid adenocarcinoma in the urinary bladder to appear in the literature. It is important to be aware of atypical cancer localizations in order to reach a correct diagnosis.