Lymphoepithelial cyst (LEC) of the pancreas: Cytomorphology and differential diagnosis on fine-needle aspiration (FNA)

Lymphoepithelial cyst (LEC) of the pancreas is nit extremely rare benign en tity. We describe the cytopathologic findings of such a lesion irt a 49-yr- old woman who was examined for epigastric pain. A trans-esophageal ultuasou nd-guided fine-needle aspiration of a pancreatic mass disclosed an intimate mixture of squamous epithelial cells and small, mature lymphocytes in a ba ckground of keratinaceous debris, anucleate squames, and multinucleated his tiocytes. On histopathologic examination, a subsequent resection showed a m ultiloculated cystic lesion with a stratified squamous epithelial lining su rrounded by well-formed lymphoid tissue, suggestive of LEC. The differentia l diagnosis includes other pancreatic pseudocysts, dermoid cyst, mucinous c ystic neoplasms, adenosquamous carcinoma, and metastatic squamous cell carc inoma. (C) 1999 Wiley-Liss, Inc.