Duodeno-Colonic Fistula Associated With an Intestinal Large B-Cell Lymphoma

Abstract

Enterocolic fistulae are usually caused by conditions such as Crohn's disease and diverticulitis. Less commonly, it can also be seen in the setting of prior surgeries, foreign bodies, pancreatitis, or malignancy. Here we reported a rare case of a spontaneous duodeno-colonic fistula caused by intestinal large B-cell lymphoma. This is a 69 year old male with a history of diabetes mellitus who presented with diarrhea and weight loss of 20 pounds for 5 weeks. He described rapid onset of 5 to 6 daily episodes of non-bloody watery stools associated with nausea, but no vomiting, abdominal pain or fever. There was no recent use of antibiotics, no recent travel or sick contacts. He has no history of Crohn's disease or diverticulitis. He was afebrile and physical exam is unremarkable. Laboratory testing revealed normal complete blood count, electrolytes, serum calcium, thyroid-stimulating hormone, and hepatic panel. A computed tomographic (CT) scan of the abdomen showed mild wall thickening and stranding surrounding the proximal duodenum and the splenic flexure of colon that was measuring up to 15 mm in diameter and multiple enlarged lymph nodes within the mesentery. Additionally, there was suggestion of a duodeno-colonic fistula. An upper endoscopy and colonoscopy were performed. Upper endoscopy revealed a fistulous tract in the transverse duodenum with refluxing of stool, however no duodenal mucosal mass seen. On colonoscopy, a large infiltrative mass with fistula near the splenic flexure was identified, but the mass was not transferable to the proximal colon. Histology was consistent with diffuse large B-cell lymphoma which stained negative for CD3 strongly positive for CD20. The patient was taken to the operating room with colorectal and hepatobiliary surgery with plans for an en bloc left colectomy, partial gastrectomy and small bowel resection and partial pancreatectomy. His post-operative course was complicated by a pancreatic duct leak which is well managed with a percutaneous drain and he will soon be initiated chemotherapy. For sudden onset of diarrhea with associated systemic symptoms suspicious for an underlying organic cause, imaging and endoscopic evaluation should be considered. The initial treatment of enterocolic fistulae is to correct fluid and electrolyte abnormalities, but in our case, oncologic treatment of B cell lymphoma could not be initiated until after surgical resolution of nutrient wasting diarrhea.1610_A Figure 1. CT showed colonic wall thickening with possible duodeno-colonic fistula1610_B Figure 2. Colonoscopy showed a large infiltrative mass with fistula near the splenic flexure.1610_C Figure 3. Pathology showed colonic mass with fistula is identified extending from the colonic mucosa to the duodenal mucosa.