Lymphoepithelial Cyst of the Pancreas: Can Common Imaging Features Help to Avoid Resesction?

Background: Differentiation of cystic pancreatic neoplasms remains a challenging task for radiologists with main aim of characterizing malignant and premalignant conditions. Purpose: The study aimed to compare radiological features of lymphoepithelial cysts (LEC) with other cystic pancreatic lesions, which could help to differentiate them in order to avoid unnecessary resection and optimize surveillance.Material and Methods: We retrospectively reviewed 12 cases of resected and histopathological confirmed LECs in last 12 years, for 10 patients imaging studies were available. 20 patients with mucinous cystic neoplasms (MCN) and 20 patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMN) were selected consecutively to serve as control groups. Imaging findings as well as clinical data were analyzed. Results: Three imaging subtypes of LEC were identified: simple cystic morphology (20%) and mixed cystic-solid lesions (80%) with either diffuse subsolid component (30%) or mural nodule (50%). All lesions revealed exophytic location with strong male predominance (9:1). MCNs were presented exclusively in middle-aged woman and IPMN in both sexes showing slight male predominance (13:7). Mean patient age in IPMN (70.5+7.7 years) was significantly higher compared to other groups (p<0.001 for LEC, p=0.005 for MCN). Unenhanced CT-attenuation of LEC was higher than MCNs (p=0.025) and IPMNs (p=0.021). Conclusion: The present study provides three imaging subtypes of LEC with key features for the differentiation from other cystic pancreatic lesions such as increased native attenuation, absence of connection to main pancreatic duct (MPD) and exophytic location. Clinical data, such as male predominance in LEC, is crucial in differentiating cystic pancreatic lesions.