Endoscopic ultrasound characteristics of pancreatic lymphoepithelial cysts: A case series from a large referral center

BACKGROUND AND OBJECTIVES: Lymphoepithelial cysts (LECs) of the pancreas are benign lesions that can mimic cystic neoplasms on imaging. Endoscopic ultrasound (EUS) features have not been well described. We aimed to describe the clinical and EUS characteristics of LECs and the present outcomes of management at a high-volume referral center. MATERIALS AND METHODS: We identified patients who underwent EUS and were found to have LECs based on fine-needle aspiration (FNA) cytology or surgical pathology from existing databases. EUS features, imaging characteristics, and pathology results were described. RESULTS: Sixteen patients were found to have 17 LECs. The mean size was 33 mm ± 15 mm. Locations within the pancreas included 10 lesions in the tail, 3 in the body, 1 in the uncinate process; the remaining 3 were exophytic. Six lesions were anechoic, 6 were hypoechoic, and 5 had mixed echogenicity. Nine lesions had mixed solid/cystic components, 7 were purely cystic, and 1 was solid. Cyst fluid was thick or viscous in six cases and thin in three. Eleven patients had diagnostic cytopathology. Six patients ultimately underwent surgery due to symptoms, nondiagnostic FNA, or other clinical concerns for malignancy. CONCLUSIONS: Pancreatic LECs have variable morphology and echogenicity on EUS, but the appearance of a cyst with variable solid and cystic components combined with the appearance of thick, turbid, and viscous aspirate should raise suspicion for an LEC. The majority of patients with LECs at our center avoided surgery for LECs on the basis of diagnostic EUS-FNA.