Lymphoepithelial cyst: a rare cystic tumor of the pancreas which mimics carcinoma.

Pancreatic cystic lesions are usually inflammatory pseudocysts (90%) or, infrequently, neoplastic processes [1]. A lymphoepithelial cyst (LEC) of the pancreas is a rare true cyst of this organ and is lined by squamous epithelial tissue surrounded by lymphoid tissue with germinal centers [2]. This rarely seen lesion should be considered in the differential diagnosis of cystic neoplasms of the pancreas. We present herein a 55-year old male who had non-specific urinary system complaints. Physical examination and blood tests were normal except for elevated serum CA 19-9 levels of 726 IU/mL (reference range: 0-33 IU/mL). An abdominal CT showed a welldefined low attenuating (30 Hounsfield units, HU) mass (7x8 cm) protruding anteriorly from the pancreatic tail (Image 1). The lesion was multiloculated with a cystic component. Our differential diagnosis included mucinous cystic neoplasms of the pancreas. A laparotomy with a left subcostal incision extending slightly to the left revealed a wellcircumscribed encapsulated mass with a multilocular cyst protruding from the pancreatic tail (Image 2). A distal pancreatectomy involving the cystic lesion without a splenectomy was carried out. The gross pathological findings disclosed a multilocular mass, measuring 7x7x6 cm filled with a pasty material. Histologically, the cyst was lined by mature keratinizing squamous epithelium supported by a layer of lymphoid