Abstract
A 65-year-old man complaining of abdominal pain was brought by ambulance. On examination, he had a fever and rebound tenderness, and abdominal computed tomography showed an enhanced cystic tumor of about 15 cm in diameter in the pelvis. Since he had ascites and increased CA19-9, emergency surgery was performed with a diagnosis of intra-abdominal tumor rupture. At operation, the tumor was 13 × 7 × 6 cm3 and located in the ileal mesentery. The appendix was normal. Although there was a moderate amount of purulent ascites, perforation was not confirmed. Partial ileal resection was performed. The resected specimen included a multi-cystic tumor with mucinous fluid collection and hemorrhagic necrosis in the cyst. Part of the tumor was exposed to the small intestinal lumen. The histopathological diagnosis was a mucus cystadenocarcinoma that originated from ileal mesentery ; most of the tumor showed low-grade dysplasia, while the remainder showed high-grade dysplasia. On immunostaining, carcinoembryonic antigen was positive, but estrogen receptor, progesterone receptor, and CA125 were negative. There was no ovarian-like stroma. A rare case of mucinous cystadenocarcinoma arising from the mesoileum is reported, along with a review of the literature.
