Enlarging lymphoepithelial cyst of the pancreas during 12 months of observation: report of a case.

Pancreatic lymphoepithelial cysts (LECs) are rare benign pancreatic cystic lesions, the etiology of which is unknown. We report a case of a pancreatic LEC, discovered incidentally in a 63-year-old man during a follow-up clinic visit for an abdominal aneurysm. Computed tomography showed a multilocular cyst, 60-mm diameter in the body of the pancreas. This cyst increased from 6.0 to 6.5 cm during 12 months of observation. Part of the cyst was also visualized on positron emission tomography imaging. Since a pancreatic cystic neoplasm could not be ruled out, we performed distal pancreatectomy and postoperative pathological examination confirmed that the lesion was an LEC of the pancreas. Despite the conclusive postoperative findings, resection is unavoidable when a true pancreatic neoplasm cannot be excluded.