A Case of Familial Adenomatous Polyposis that Developed Primary Carcinoma of the Appendix

Abstract

Four years previously, the patient had undergone colonoscopy in our institution during which over 100 polyps were identified, and after genetic screening, non-concentrated familial adenomatous polyposis (FAP) due to a nonsense mutation in the APC gene was diagnosed. The patient refused surgery and remained under observation while undergoing regular yearly endoscopy to remove the polyps. The patient subsequently presented with right lower abdominal pain that had persisted for 2 days. Appendicitis was suspected on the basis of blood tests and abdominal computed tomography, and the decision was made to perform emergency surgery that day. Because appendiceal cancer could not be excluded, an open appendectomy was performed, and since intraoperative rapid pathological testing resulted in a diagnosis of mucinous carcinoma of the appendix, ileocecal resection and lymph node dissection were also performed. The case of a patient with FAP who developed primary appendiceal cancer, a rare occurrence, is reported along with a short discussion of the literature.