Lessons learned from 29 lymphoepithelial cysts of the pancreas: institutional experience and review of the literature

Abstract

Differentiating LECs from premalignant pancreatic cystic neoplasms remains difficult. Findings of an exophytic growth pattern of the lesion on abdominal imaging and the presence of specific cytomorphologic features in the EUS-FNA biopsy could help clinicians diagnose LEC preoperatively.

A Rare Presentation of Pancreatic Lymphoepithelial Cyst: A Case Report and Review

“…Pancreatic LEC predominantly occurs in males aged 50 to 60 years [3,6,7,12,14,15], which is on par with when the patient in our case initially presented. It is commonly an incidental finding, albeit patients may present with nonspecific symptoms such as abdominal pain and nausea [9,12,16,17].…”

“…It is commonly an incidental finding, albeit patients may present with nonspecific symptoms such as abdominal pain and nausea [9,12,16,17]. Majority of the LECs are well-defined, round, anechoic, or hypoechoic complex cystic lesions with enhancing septa or rim, uniformly distributed in an exophytic location around the head, body, and tail of the pancreas [3,7,15,18,19]. However, these features can overlap with other types of pancreatic lesions such as intraductal papillary mucosal neoplasms or mucinous cystic neoplasms which have malignant potential, leading to unnecessary surgical intervention.…”

“…Hence cytopathological evaluation through EUS-FNA has become the mainstay to increase accuracy of diagnosis for pancreatic LECs. LEC tends to have common distinct features comprised of an outer layer of lymphoid tissue and an inner layer of mature, nucleated squamous epithelium without atypia [2,3,6,15,16,24,25]. Most specific cytopathological features include cholesterol crystals, keratin, and squamous cells, or fragments [26].…”

“…Currently, there are a limited data in the U.S. regarding the sensitivity and specificity of EUS in diagnosing LECs given broad differential diagnoses of pancreatic cysts. In one recent retrospective study, only 10 out of 29 patients with LEC had the diagnosis exclusively based on imaging (EUS and CT) [15]. us, tissue acquisition via EUS-FNA can be very useful in distinguishing specific types of pancreatic lesions and should be utilized to work up suspected LEC [30].…”

Practical Applications of Molecular Testing in the Cytologic Diagnosis of Pancreatic Cysts

“…The subepithelial stroma consists of dense, non-neoplastic lymphoid tissue with germinal center formation that may not be as well-represented on the FNA mateial as compared to the squamous epithelial component. Cytology shows anucleated and nucleated squamous cells with abundant keratinous debris, variable cholesterol crystals, lymphocytes, and histiocytes [23,24]. Importantly, there are pitfalls to consider in the differential diagnosis between LECs and mucinous cysts.…”