Abstract
An 80-year-old man was admitted with rectal cancer. Abdominal CT scan and MRI examination revealed an approximately 12-cm cystic tumor with calcification and a solid enhanced region. We operated on him based on the diagnosis of rectal cancer and mesenteric carcinoma or duplication of the intestine or gastrointestinal stromal tumor. The operative findings showed expansive growth of an approximately 13 cm × 6 cm × 5 cm tumor that was 40 or 50 cm into the intestinal mesenterium from the ileum end. It was enucleated without resection of the intestine. On the basis of pathological analysis, the tumor was diagnosed as adenocarcinoma of a small intestinal mesenteric cyst.
Adenocarcinoma of a mesenteric cyst is rare ; to our knowledge this is the second case of adenocarcinoma of a mesenteric cyst in Japan.
