S1752 Medullary Carcinoma of the Colon Presenting as Sepsis in a Patient With Ulcerative Colitis and Primary Sclerosing Cholangitis

Abstract

Introduction: Medullary carcinoma (MC) of the colon is a rare histological subtype of poorly differentiated adenocarcinoma representing approximately 5-8 cases of every 10,000 colon cancers diagnosed. The prevalence of inflammatory bowel disease in patients with primary sclerosing cholangitis (PSC) ranges upwards of 50%, and the combination of both ulcerative colitis (UC) and PSC leads to a fourfold increase of colorectal cancer. Here we present a case of medullary colon cancer presenting as bilateral deep vein thrombosis (DVT) and sepsis, and to date there have been no reports of primary colonic MC in a patient with PSC. Case Description/Methods: A 30-year-old African American man with a history of UC on mesalamine and PSC on ursodiol presented with anemia and hematochezia. It was thought that he was having an UC flare and was treated with steroids. Colonoscopy showed multiple anal and rectal ulcers. Shortly after, he was diagnosed with bilateral lower extremity DVT, requiring placement of an IVC filter. He then developed sepsis, at which point he was diagnosed with E. coli bacteremia. CT scan showed a right lower quadrant necrotic and exophytic mass with surrounding adenopathy concerning for malignancy (Figure 1). Laboratory results demonstrated leukocytosis of 25.5, microcytic anemia with hemoglobin 7.6 g/dl and MCV 67.2 fl, thrombocytosis of 513 x 103/µL, elevated alkaline phosphatase of 574 U/L with total bilirubin of 1.9 mg/dL of which direct bilirubin was 1.3 mg/dL. SGOT 39 U/L, SGPT 58 U/L, GGTP 360 U/L. Carcinoembryonic Antigen (CEA) was elevated to 3.3 ng/mL. Colonoscopy demonstrated a large friable mass located in the ascending colon that appeared malignant and spanned approximately 4 cm (Figure 2). After undergoing a right hemicolectomy, pathology demonstrated poorly differentiated colonic MC with invasion through the muscularis propria (T3), with metastatic carcinoma identified in 8 of 43 lymph nodes (N2b). Discussion: Colonic MC tumors tend to be located proximally, rarely present with metastasis, and have been strongly associated with hereditary nonpolyposis colorectal cancer. It is twice more common in females and the mean age at diagnosis is 69.3±12.5 years. It is extremely rare in African Americans. These tumors can be difficult to distinguish from poorly differentiated adenocarcinomas and neuroendocrine tumors, but presence of positive calretinin staining in MC confirms diagnosis. This is the first report of MC of the colon in an individual with PSC, and one of the few in patients with UC.Figure 1.: A. CT abdomen/pelvis without contrast demonstrating a diffusely dilated, air-filled gastrointestinal tract extending from the stomach through the rectosigmoid colon. No transition point or obstruction noted. B. CT abdomen/pelvis with rectal contrast demonstrating an interposition of the hepatic flexure of the colon posterior and medial to the right lobe of the liver. No evidence of obstruction or strangulation noted. C. Endoscopy demonstrating a twisted, almost volvulus-like appearance at the splenic flexure, though without clear transition points.