Poorly Differentiated Neuroendocrine Carcinoma of the Sigmoid Tract in Long-Standing Ulcerative Colitis: Report of a Case and Review of the Literature

A 37-year-old male with long-standing and extensive ulcerative pancolitis developed a rapidly lethal poorly differentiated neuroendocrine carcinoma (NEC) in the sigmoid colon. Prior biopsies obtained from multiple sites of the colon during endoscopic surveillance showed minimal inflammatory changes and no sign of dysplasia. Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal malignancies, and adenocarcinoma is the...