A Rare Case of Sigmoid Adenocarcinoma Presenting with Coloenteric, Colosubcutaneous, and Colovesicular Fistulas

Abstract

Fistulous complications occur in less than 10% of colon cancers as a result of locally advanced disease. We present an unusual case of a patient presenting with multiple fistulous tracts extending from the sigmoid colon to the small intestine, urinary bladder and skin, who was subsequently found to have locally advanced adenocarcinoma of the sigmoid colon. A 67-year old female presented to the emergency department with generalized fatigue and left-sided flank pain. Medical history included: breast cancer treated with chemoradiation and right radical mastectomy 3 years prior, chronic iron deficiency anemia and morbid obesity. Physical exam was notable for normal vitals and diffuse non-tender fluctuance along her left flank. Computed tomography imaging revealed a large subcutaneous air/fluid collection that extended along the left lateral abdominal wall that communicated with an inflamed sigmoid colon via a fistulous tract. There were also fistulous tracts extending from the sigmoid colon to the ileum and urinary bladder. Flexible sigmoidoscopy showed an obstructing, circumferential exophytic and friable mass. Urgent incision and drainage of the left flank fluid collection yielded feculent material. Left hemicolectomy with transverse colostomy and terminal ileal resection with primary anastomosis performed a few days later. Histopathology confirmed a 6cm x 5cm invasive adenocarcinoma with invasion of viscera, peritoneum, abdominal wall with clear surgical margins and 0/19 lymph nodes (pT4bN0M0). Following multiple washout and debridement procedures, her flank wound was eventually closed. Post-operatively she did well and adjuvant chemotherapy was initiated. Fistulas are an uncommon complication of locally advanced colonic adenocarcinoma, in part due to earlier diagnosis of colon cancer, and occur most frequently in sigmoid colon cancers. Rarely do patients have fistulous complications as an initial presentation of their colon cancer. We speculate that this patient's malignancy had an exuberant inflammatory component given the extensive fistulizing disease without lymph node nor distant organ involvement. To our knowledge this is the first reported case of a patient initially presenting with multiple fistulous complications as a result of a locally advanced sigmoid adenocarcinoma.1520_A Figure 1. Endoscopic view of sigmoid mass1520_B Figure 2. Computerized tomography of colosubcutaneous fistula1520_C Figure 3. Computerized tomography of colovesicular fistula