A case of a resected primary lymphoepithelial cyst of the pancreas

A 63-year-old man visited a local hospital because of upper abdominal discomfort. He was diagnosed with pancreatic cystic disease, and referred to our hospital. Blood chemistry showed elevated levels of CA19-9 (90.3U/l) and Span-I (45U/ml). Abdominal CT revealed a large 10-cm cyst containing a 2-cm, node-like structure with contrast enhancement. ERCP showed that the cyst did not communicate with the main pancreatic duct, but compressed it. At surgery, a softball-sized tumor was observed in the pancreatic head. It was straightforward to dissect from the stomach, but difficult to free the pancreas, particularly a portion in the head, which was diagnosed as the site from which the cyst arose. The cyst contained a gruel-like fluid with plasma components, as well as a 2-cm nodule on its dorsal side. Histopathological examination revealed a cystic lesion containing keratinized material and lined with stratified squamous epithelium, which was immediately underlain by lymphatic tissue. These findings led to a diagnosis of lymphoepithelial cyst.