Enterovesical fistula caused by non-Hodgkin's lymphoma of the ileum: report of a case.

We herein present a rare case of enterovesical fistula caused by ileal non-Hodgkin's lymphoma. A 75-year-old Japanese male presented with macrohematuria at Kosei General Hospital in December 2010. An egg-sized mass was palpable in his right lower abdominal region, and computed tomography (CT) revealed that the ileal tumor had invaded the right posterior wall of the urinary bladder (UB). A histopathological examination of a CT-guided needle biopsy specimen revealed diffuse large B-cell lymphoma involving the ileum and the UB. Thereafter, fecaluria appeared. A transurethral catheter was put in place, and there were no symptoms of cystitis. The patient received chemotherapy for the lymphoma, which produced a partial response. However, the fecaluria continued, and an examination of the small intestine with contrast revealed a thick and irregular wall of the ileum and a fistula between the ileum and UB. A partial resection of the ileum and a partial cystectomy were carried out in April 2011. The surgical specimen demonstrated two tumors 5 cm apart in the ileum, measuring 4.5 × 7 and 4 × 3 cm in size. The proximal tumor had directly invaded the UB and formed an ileovesical fistula. The patient made a good recovery and was doing well 5 months after the surgery without any evidence of recurrence.