Abstract
We report a case of pseudocyst of the jejunal mesentery in an adult patient. A 34-year-old woman was admitted for a palpable abdominal mass of increasing size. The patient had a medical history of a indirect inguinal hernia and no injury. Abdominal ultrasonography and computed tomography revealed an apparent unilocular cyst about 7 cm in diameter. Abdominal magnetic resonance revealed that the superior component of the cyst was hyperintense on T2 images and even more so on T1 images, and the inferior component of the cyst was hyperintense on both T1 and T2 images. We made a preoperative diagnosis of a cyst of the jejunal mesentery. After laparotomy, the cystic mass, which indeed measured 7 cm in diameter, was found in the mesentery of the jejunum and was resected. The content of the cyst was pale yellow muddy fluid. Microscopically, its wall consisted of fibrous tissue without an epithelial lining, suggesting that it was a pseudocyst arising from the jejunal mesentery. Such pseudocysts of the mesentery are extremely rare, there are only nine cases including ours in the literature in Japan.
