Clinical Characteristics of Patients With Ulcerative Colitis and Small Intestinal Malignancy.

Background: Prior studies have examined small intestinal dysplasia and cancer in Crohn's disease; however, there is limited information on ulcerative colitis (UC). We describe characteristics of small intestinal dysplasia and cancer in patients with UC. In this study, we aimed to identify common characteristics between patients with UC that were diagnosed with small intestinal malignancy. Methods: Electronic medical records were reviewed for 3 tertiary referral centers to identify patients with a diagnosis of UC and small intestinal dysplasia or cancer between 2010 and 2023. Data collection included demographics, family history of gastrointestinal malignancy, UC diagnosis date, duration and location of disease, prior UC medical treatment or surgery, diagnosis of primary sclerosing cholangitis (PSC), PSC-related complications, and details of cancer or dysplasia. Descriptive statistics were performed. Results: Thirty-five patients (60% male, mean age of diagnosis 39.3 ± 21.5 years old) were identified with UC and subsequent small intestinal dysplasia or cancer. Most had pancolitis (74.3%) or pancolitis with backwash ileitis (8.57%). Half underwent surgery for their UC, and half of these had the cancer or dysplasia found at the time of surgery. Ileal dysplasia was found in 2 patients (5.71%), duodenal adenocarcinoma in 2 (5.71%), ileal adenocarcinoma 2 (5.71%), duodenal carcinoid in 4 (11.4%), ileal carcinoid in 24 (68.6%), other duodenal neuroendocrine tumor in 1 (2.86%). Primary sclerosing cholangitis was diagnosed in 5 patients (14%), and 3 required liver transplants. Conclusions: Small intestinal dysplasia and cancer are rare in this population. Most patients with small intestinal cancer or dysplasia were male, Caucasian, and had a history of extensive colitis. Ileal carcinoid had the highest incidence. Gastroenterologists should be aware of this finding in patients with UC.