Appendiceal Adenocarcinoma Presenting as a Rectal Polyp

We report on a case of a primary appendiceal cancer initially diagnosed as a rectal polyp based on its appearance in the rectal lumen. The management of the patient was in keeping with standard practice for a rectal polyp, and the diagnosis of appendiceal adenocarcinoma was made intraoperatively. The operative strategy had to be adjusted due to this unexpected finding. Although there are published cases of appendiceal adenocarcinoma inducing intussusception and thus mimicking a cecal polyp, there are no reports in the literature describing invasion of the appendix through the rectal wall and thus mimicking a rectal polyp. The patient is a 75-year-old female who presented with spontaneous hematochezia and, on colonoscopy, was noted to have a rectal polyp that appeared to be located within a diverticulum. When endoscopic mucosal resection was not successful, she was referred to colorectal surgery for a low anterior resection. Preoperative imaging was notable for an enlarged appendix adjacent to the rectum. Intraoperatively, the appendix was found to be densely adherent to the right lateral rectal wall. An en bloc resection of the distal sigmoid colon, proximal rectum and appendix was performed, with pathology demonstrating appendiceal adenocarcinoma that invaded through the rectal wall. The prognosis in this type of malignancy weighs heavily on whether or not perforation and spread throughout the peritoneal cavity have occurred. In this unusual presentation, an en bloc resectio...
Source: Case Reports in Gastroenterology - Category: Gastroenterology Source Type: research