A chylous cyst of the mesentery: Report of a case

A case is presented of an adult chylous cyst of the mesentery that was preo peratively diagnosed to be a pancreatic cystadenoma. A 66-year-old asymptom atic male was followed up for 15 months under the diagnosis of a benign pan creatic cyst. On October 1997, computed tomography showed a 45 x 40 mm cyst ic mass in the upper abdomen which came in contact with the pancreas. Endos copic ultrasonography revealed a multilocular mass with a 7 x 4 mm elevated lesion. Endoscopic retrograde cholangiopancreatography and magnetic resona nce cholangiopancreatography revealed the cystic mass to be unrelated to th e pancreatic duct. The preoperative diagnosis was a pancreatic cystadenoma or cystadenocarcinoma. A laparotomy showed a 50 x 40 mm cystic mass contain ing chylous fluid, that arose from the mesentery of the upper part of the j ejunum, The pathological diagnosis was a chylous cyst of the mesentery. The preoperative diagnosis in this case was very difficult because the chylous cyst appeared to be attached to the pancreas and this phenomenon is consid ered to be extremely rare.