Lymphoepithelial cysts of the pancreas: an EUS case series.
BACKGROUND
Lymphoepithelial cysts (LEC) of the pancreas are rare benign lesions that can be misdiagnosed as pancreatic masses or cystic neoplasms. With widespread use of abdominal cross-sectional imaging, more pancreatic lesions are being discovered, with EUS being used to further evaluate the abnormality.


OBJECTIVE
Our purpose was to describe EUS and cyst aspirate features of LEC of the pancreas.


METHODS
Case series.


METHODS
Single tertiary referral center.


METHODS
Nine patients with lymphoepithelial cysts who underwent EUS-FNA.


RESULTS
Five male and 4 female patients were identified (mean age 51 years). All lesions were discovered by CT and described as "peripancreatic" in 67% of cases (6/9). EUS examination described a solid-appearing hypoechoic and heterogeneous mass with subtle postacoustic enhancement in 5 of 9 cases. Four lesions were described as purely cystic: 2 were septated, 1 was unilocular, and 1 had internal papillary fronds. Mean cyst size was 5.2 cm (range 1.7-12 cm). Cyst aspirates revealed a thick milky, creamy, or frothy aspirate in 56% of cases (5/9). Cyst cytologic examination revealed squamous material (nucleated/anucleated cells or keratin debris) in all cases. Lymphocytes were seen in 56% of aspirates (5/9). Carcinoembryonic antigen (CEA) levels were obtained in 5 cases (median 6.5 ng/mL [range 2.9-493.4 ng/mL]). Six patients have avoided surgery on the basis of EUS-FNA cytologic results confirming the diagnosis of LEC. Three patients underwent surgical resection: 2 for symptomatic lesions and 1 for concern for a mucinous cystic neoplasm given an elevated aspirate CEA level. Surgical pathologic examination confirmed LEC in each.


CONCLUSIONS
Retrospective single-center study.


CONCLUSIONS
LEC should be considered whenever a large, well-defined solid or cystic peripheral pancreatic lesion is found. A thick milky, creamy, or frothy aspirate is common. The presence of squamous material and lymphocytes on cytologic examination is diagnostic of LEC. Aspirate CEA level may be elevated and should be considered in conjunction with cytologic results to avoid misdiagnosis as a mucinous cystic neoplasm. Asymptomatic LEC should be managed conservatively.
Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 16046, USA.
John
J
Nasr
Michael
M
Sanders
Kenneth
K
Fasanella
Asif
A
Khalid
Kevin
K
McGrath
D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle / Q000379:methods*; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D035583:Rare Diseases; D012189:Retrospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index