Small bowel fistula with colorectal cancer and mesenteric lymph node metastasis: a report of two cases.

A 65-year-old man presented to our hospital with complaints of diarrhea. Computed tomography showed a fistula with the small intestine, and a single incision laparoscopic low anterior resection for rectum with D3 dissection and partial resection of the small intestine were performed. Lymph node dissection, including a part of the inflow vessel area, was also performed because lymph node swelling was observed in the mesentery of the small intestine around the fistula. Histopathological analysis revealed that the lymph nodes in the small intestine were positive for metastasis. The patient was a 61-year-old woman who presented to our hospital with a chief complaint of diarrhea. A partial resection of the small intestine, including resection of the left hemicolectomy and lymph node dissection around the fistula, was performed at laparotomy. Histopathological examination revealed numerous lymph node metastases in the small intestinal mesentery.