S3404 Medullary Carcinoma of Colon Found in a Patient With Ulcerative Colitis and Primary Sclerosing Cholangitis

Abstract

INTRODUCTION: Medullary carcinoma of the colon is a relatively rare entity that is observed in only 5 to 8 cases for every 10,000 colon cancers diagnosed. It usually presents in the right colon, and it is more common in African Americans and patients with Lynch syndrome. Diagnosis is made on histology with expression of markers such as calretinin and CK7. CASE DESCRIPTION/METHODS: A 30-year-old African American man with a past medical history of ulcerative colitis on mesalamine and primary sclerosing cholangitis presented originally to an Trinitas Hospital with anemia and hematochezia. At the time, it was thought that he was having an ulcerative colitis flare, and he was treated with steroids. He underwent a colonoscopy with evidence of multiple anal and rectal ulcers. Around that time he was found to have bilateral lower extremity DVTs and an IVC filter was placed. He was readmitted shortly after discharge back to Trinitas and was found to be septic with e. coli bacteremia. A CT scan showed a right lower quadrant necrotic mass and he was transferred to University Hospital in Newark for further work-up as it is unclear if this mass is infectious or malignant and he will require surgical evaluation. On repeat colonoscopy, it was found that there was a large, friable mass located in the ascending colon that appeared malignant and spanned 3-4 cm. It was transversable with the colonoscope. Multiple biopsies were taken with cold forceps. Additionally, hot snare was used to cut off a larger segment which was retrieved with a basket. Pathology initially returned showing adenocarcinoma, but upon further examination, additional markers and immunostains were applied, and a final diagnosis of primary medullary carcinoma of the colon was made. Due to suspicious looking mass as well as patient's continued anemia, resection was offered and the patient accepted. Resection completed surgically with no immediate post-operative complications. DISCUSSION: To date, no reports of primary medullary carcinoma of the colon has been diagnosed in a patient presenting with primary sclerosing cholangitis, and only one case found in a patient with ulcerative colitis. In general, medullary carcinoma of the colon has a more favorable prognosis than adenocarcinoma of similar staging, with an overall 5-year survival rate of ∼65%. Treatment can consist of chemotherapy with oxaliplatin-xeloda.