Small Intestine Neuroendocrine Tumor in a Patient With MUTYH Adenomatous Polyposis-Case Report and SEER Analysis

Both MUTYH adenomatous polyposis syndrome and small intestinal neuroendocrine tumors (NETs) are rare. The typical features of MUTYH adenomatous polyposis syndrome are > 10 adenomatous colorectal polyps by age 60 years; also associated are hyperplastic polyps, adenomatous duodenal polyps, and gastric fundic gland polyps. The lifetime risk of colorectal cancer with MUTYH adenomatous polyposis syndrome is 50% to 90%. Small intestinal neuroendocrine tumors (NETs) have been reported in patients with sporadic colonic neoplasms, ulcerative colitis, Crohn disease, Lynch syndrome, CHEK2 mutation, and familial adenomatous polyposis. An association might also exist between small intestinal NETs and MUTYH adenomatous polyposis syndrome that clinicians should be aware of when treating patients with this syndrome. (C) 2018 Elsevier Inc. All rights reserved.