[A Case of Lymphoepithelial Cyst of the Pancreas for Which Malignancy Could Not Be Ruled Out Difficult Preoperative Diagnosis].

Lymphoepithelial cyst(LEC)of the pancreas is a relatively rare benign cystic disease of the pancreas. In this report, we describe a case of LEC in which a malignant tumor could not be ruled out by preoperative diagnosis and surgery was performed. The patient was a 72-year-old man. A simple CT scan of the chest and abdomen performed as a follow-up for another disease incidentally revealed a mass in the pancreatic tail. Enhanced CT of the abdomen showed a tumor approximately 3 cm in size at the pancreatic tail with no contrast effect. MRCP showed moderate signal on T2WI, high signal on T1WI, and high signal on T2WI on some cysts inside the pancreas. PET-CT showed slight uptake of FDG. Both tumor markers CEA and CA19-9 were normal. Therefore, malignant disease such as pancreatic IPMC could not be ruled out, and laparoscopic distal pancreatectomy plus splenectomy was performed. The pathology results showed a diagnosis of pancreatic lymphoepithelial cyst with slight differentiation into sebaceous gland.