1606 A Very Unusual Case of Colonic Adenocarcinoma Originating From an Enterocutaneous Fistula

Abstract

INTRODUCTION: Enterocutaneous fistulas are a well known sequelae of intrabdominal surgeries. Common complications of these fistulas include sepsis, electrolyte abnormalities, and nutritional deficiencies. We present an unusual case of a mucinous colonic adenocarcinoma originating from an enterocutaneous fistula. To our knowledge, there are no other known cases of colonic adenocarcinoma originating from an enterocutaneous fistula. CASE DESCRIPTION/METHODS: Patient was a 65-year-old male with a past medical history significant for Korsakoff dementia and OLT ten years ago who presented to GI clinic. He had complaints of weight loss, decreased appetite, and increased lethargy. The patient had an enterocutaneous fistula as a result of a bowel resection following perforation from ERCP nine years prior. The fistula was never repaired as the patient was thought to be a poor surgical candidate and it did not seem to interfere with his quality of life. Physical exam was notable for a tender abdomen with several scattered erythematous and excoriated lesions. There was an ostomy bag covering a 10cm fungating, necrotic appearing, malodorous mass with greenish liquid in the ostomy bag (Figure 1). This was surrounding the fistula site. Based on CT abdomen results from six months prior, it was suspected that this was an enterocutaneous fistula that may connect to the transverse colon. Biopsies were taken at bedside which revealed mucinous moderately differentiated adenocarcinoma, morphologically suspicious for colonic-type adenocarcinoma (Figure 2). Repeat CT abdomen showed a large heterogeneous abdominal wall lesion and mild wall thickening of adjacent mid-transverse colon consistent with the known mass. DISCUSSION: The prevalence of enterocutaneous fistulas in the population is not known; most are iatrogenic or postoperative in etiology (75-85%), with the ileum being the most common location. This patient’s enterocutaneous fistula was never repaired and was likely the result of a bowel resection following perforation from ERCP several years prior. As with chronic inflammatory states, such as that seen in IBD which can predispose to colorectal cancer, we hypothesize that a similar mechanism of chronic inflammation from a fistula connection to the outside environment may have contributed to this patient developing a colonic malignancy, especially in the setting of his immunosuppression. Furthermore, in patients who are unable to undergo repair of enterocutaneous fistulas, their risk of colorectal cancer may be increased.