Lymphoepithelial cyst of the pancreas: report of a case.

An extremely rare case of a lymphoepithelial cyst (LEC) of the pancreas is described herein. A pancreatic cystic tumor was initially detected in a 50-year-old man at a medical checkup. On admission, his serum carbohydrate antigen (CA) 19-9 level was 8100 U/ml and a computed tomography scan revealed a well-circumscribed multilocular cystic tumor in the pancreatic head and body. Magnetic resonance cholangiopancreatography showed no communication between the pancreatic ducts and the tumor. A distal pancreatectomy with lymph node dissection was performed because the lesion was suspected to be a mucinous cystadenoma or cystadenocarcinoma of the pancreas. However, histological examination revealed that the cyst was lined by stratified squamous epithelium and surrounded by lymphoid tissue. thereby confirming the diagnosis of LEC of the pancreas. The superficial layer of squamous epithelium and the cystic contents were found to be immunohistologically positive for CA19-9. Establishing a preoperative diagnosis of LEC is quite difficult because it resembles other cystic neoplasms of the pancreas in radiographic features and is frequently associated with an elevation of serum tumor markers such as CA19-9.