Vomiting and profound weight loss as a clue to the diagnosis of malignant coloduodenal fistula

Abstract

Colon cancer generally presents with lower gastrointestinal symptoms, such as diarrhea, constipation, and general abdominal discomfort; it is rare for the primary presentation to have upper gastrointestinal symptoms. We report a patient with coloduodenal fistula secondary to colon malignancy who presented with incessant vomiting and dramatic weight loss as the chief complaint. It is important to consider colon cancer as part of the differential in patients with atypical presentations of upper gastrointestinal symptoms who have known colon cancer risk factors.

Coloduodenal fistula is a rare condition commonly seen secondary to inflammatory bowel disease or diverticulosis. Colon cancer usually presents with lower gastrointestinal (GI) symptoms, such as diarrhea, constipation, hematochezia, and general abdominal discomfort. It is unusual for colon cancers to present primarily with upper GI symptoms. However, when advanced local colon cancer creates a coloduodenal fistula, patients may have upper GI symptoms as the initial presenting sign of the underlying malignancy. Here, we present a patient with coloduodenal fistula secondary to colon malignancy who presented with incessant vomiting associated with dramatic weight loss.

CASE DESCRIPTION

A 55-year-old man with no significant past medical history presented with a 55-pound weight loss in 3 months, abdominal pain for 1 year, and nausea, vomiting, and constipation for 2 months. Initial workup showed severe anemia with a hemoglobin of 8.2 g/dL. Computed tomography (CT) of the abdomen demonstrated a 9.9 × 10.1 cm right upper abdominal mass that appeared to originate in the colon and extend into and invade the descending segment of the duodenum with duodenal fistulation (Figure 1). Magnetic resonance imaging of the abdomen confirmed the invasion of the colonic mass into the second and third portion of the duodenum. Upper GI endoscopy revealed a large infiltrative and submucosal mass in the second part of the duodenum. A colonoscopy showed an ulcerative mass completely obstructing the proximal transverse colon (Figure 2). The histopathologic examination of the mass confirmed colonic adenocarcinoma, which led to the diagnosis of malignant coloduodenal fistula.

Figure 1.

CT of the abdomen showing a 9.9 × 10.1 cm colon mass invading into the adjacent duodenum with fistula.

Figure 2.

Esophagogastroduodenoscopy and sigmoidoscopy showing an ulcerated mass in the second part of the duodenum and transverse colon.

During admission, the patient was anemic and required multiple blood transfusions. His clinical condition deteriorated rapidly with development of complete bowel obstruction symptoms, including the absence of flatulence and bowel movements and intractable vomiting. He underwent surgical treatment with loop ileostomy and enteral feeding to relieve the obstructive symptoms, which also led to improvement in his malnutrition status.

DISCUSSION

Coloduodenal fistula associated with colon cancer is rare and is associated with a poor prognosis without timely management. Previous studies have shown that the most common causes of coloduodenal fistulas are Crohn’s disease, diverticulosis, gallstones, and pancreatic pseudocyst.^1,2 Although several case reports and case series have reported coloduodenal fistula in colorectal carcinoma, in the United States, due to early screening, it is rare for colon cancers to invade the duodenum and form a malignant fistula.³ Previous literature has reported that 1 in 900 patients with colorectal carcinoma can progress to develop coloduodenal fistula.⁴

Symptoms can arise from primary tumors or from the fistula. Most patients with colon cancer present with lower GI symptoms; however, people with malignant coloduodenal fistula may present with upper GI symptoms associated with other atypical symptoms, such as dramatic weight loss, nausea, and vomiting of feculent or totally fecal contents. Patients may also present with diarrhea due to duodenal bile salt irritation. There may be hematemesis due to esophageal tears secondary to prolonged episodes of upper GI irritation leading to recurrent emesis. Unusual presentations, such as upper GI bleeding, delay the diagnosis of colon cancer, leading to further complications.

CT imaging is helpful for the localization of tumor and surgical planning. In general, definitive management of coloduodenal fistula is surgical resection, specifically tumor and fistula en bloc with adequate lymph node removal.^1,5,6 Prior to surgery, patients are managed with fluids, nasogastric tube feedings, and strict input and output monitoring. Ileostomy and percutaneous endoscopic gastronomy have been performed in coloduodenal fistula patients for both gastric drainage and distal enteral feeding.⁴ If enteral feeding is impossible, improving nutrition and optimizing electrolytes through preoperative total parenteral nutrition is an alternative.⁶ Patients with locally advanced colon cancer may require pancreatoduodenectomy.⁷ The prognosis depends on the extent of tumor invasion and whether the current presentation is a recurrence of a previously resected tumor.^6,7 Previous case reports have shown that appropriate resection of diseased tissue allows for a disease-free survival of up to 37 months after the surgery, and the median survival rate is 14 months.^7,8

In a patient who presents with upper GI symptoms of vomiting and nausea and has risk factors for colon cancer or has a previous diagnosis of colon cancer, colon cancer should remain in the differential, despite the atypical presentation.