Synchronous primary adenocarcinoma of the appendix and colon: Case report and literature review

INTRODUCTION: Primary adenocarcinoma of the appendix (PAA) is rare with fewer than 300 cases reported from 1882 Up to 2004. Synchronous occurrence of PAA with a second primary colonic carcinoma is even more unusual. Literature review shows a total of 40 reported synchronous cases in the English literature from the first case reported in1947 up to 2017. Hereby, an additional case is presented, which is the first case reported in Jordan. PRESENTATION OF CASE: A 39-year-old woman presented in October 2016 with persistent right lower quadrant abdominal pain diagnosed clinically as acute appendicitis. Abdominal computed tomography showed an oval shaped 3 × 3.4 cm mass at the sub-hepatic region, associated with increased attenuation of surrounding mesenteric fat and multiple enlarged lymph nodes. Three days later, a right hemicolectomy was carried out. A diagnosis of invasive primary adenocarcinoma of the ascending colon with an incidental, microscopic primary adenocarcinoma of the distal part of the appendix was reported. DISCUSSION: Primary appendiceal adenocarcinoma is rare pathology with an incidence ranges from 0.01% to 0.3% that is characterized by presence of adenocarcinomatous cells originating in the appendix that are in direct continuity with the normal appendiceal mucosa. Even it is less common, synchronous primary adenocarcinoma of the appendix and the colon has been reported in literature, with less than 37 cases being reported in literature so far. PAA are seldom suspected in preoperative phase or even intraoperatively, and it is diagnosed based on histopathologic examination of the resected appendix. Once PAA is diagnosed, a lifelong surveillance with colonoscopy is mandatory to detect synchronous or metachronous colonic malignancies. CONCLUSIONS: Once a diagnosis of primary appendiceal adenocarcinoma is proved histologically, it is it is warranted to perform surveillance for synchronous or metachronous tumors because of the increased risk of a second primary malignancy in the gastrointestinal tract.