Lymphoepithelial cyst of pancreas. Role of endoscopic ultrasound guided fine needle aspiration.

Lymphoepithelial cysts of the pancreas are extremely rare, benign, nonneoplastic cysts that may simulate pseudocysts or cystic neoplasm of the pancreas. Endosonographic and cytologic features of pancreatic lymphoepithelial cysts are poorly characterized because of their rarity. However, appropriate prospective diagnosis of pancreatic lymphoepithelial cysts using endoscopic ultrasound-guided fined needle aspiration (EUS-FNA) cytology may permit conservative management because of their benign nature. We conducted a MEDLINE search using the MeSH terms "pancreas", "cyst" and identified 16 patients who were diagnosed with endosonography or computerized tomography (CT) guided fine needle aspiration. Usefulness and pitfalls of EUS- or CT-guided cyst fluid analysis in the pre-operative diagnosis of pancreatic lymphoepithelial cysts are discussed.