A Case Report of the Mucinous Adenocarcinoma of the Small Intestine that has a Vesicointestinal Fistula

A 72-year-old woman referred for low abdominal discomfort was found in urinalysis to have hematouria. Cystoscopy by urologist found a tumor at the top of the bladder, necessitating transuteric resection of the bladder tumor. The tumor had invaded the serosa and resection was incomplete. Microscopic findings of the specimen indicated adenocarcinoma, suggesting that the tumor had originated in either the right ovary or small intestine rather than the bladder, so another examination was made. Computed tomography and magnetic resonance imaging showed a tumor in the pelvic space outside the bladder. Blood tests showed high CA 19-9.Scintigraphy showed radioisotope leakage of the bladder into the small intestine, and cystography revealed a vesicointestinal fistula. Small bowel cancer or ovarian cancer invasion of the small intestine and bladder was suspected, necessitating surgery. Intraoperative findings showed small bowel cancer invading the bladder directry with vesicointestinal fistula, requiring partial iliotectomy and total cystectomy. The histopathological finding was mucinous adenocarcinoma. To our knowlage, there have been few reports of small intestinal carcinoma such as this with vesicointestinal fistula.