[Case with gradually enlarging lymphoepithelial cyst of the pancreas that necessitated enucleation].

A 54-year-old man exhibited a pancreatic mass on abdominal ultrasonography. Diagnostic imaging with endoscopic ultrasonography, computed tomography, and magnetic resonance imaging revealed that the mass comprised various internal structures and was not connected to the pancreatic duct. Over a period of 4 years and 2 months, the mass increased from 22mm to 32mm in diameter. Laparoscopic enucleation was performed, and a histopathological diagnosis of a lymphoepithelial cyst (LEC) of the pancreas was obtained. LEC is rare and seldom reported in the literature. Although it is considered to be benign, most case reports indicate that they tend to increase in size. This indicates that LEC should be carefully monitored if surgery is not performed after diagnosis.