Fine-needle aspiration cytology of pancreatic lymphoepithelial cysts

Abstract

BACKGROUND. Lymphoepithelial cysts (LECs) of the pancreas are extremely rare, benign, nonneoplastic cysts that can mimic pseudocysts or cystic neoplasms clinically and radiographically. The cytologic features of LECs have been described only in a handful of case reports and may overlap with both benign and malignant pancreatic tumors. METHODS. The authors conducted a 5‐year, retrospective, computerized review of the cytopathology files of 2 institutions for all diagnoses of pancreatic LECs. Clinical, radiographic, cytologic, and chemical findings were reviewed. RESULTS. Four patients were identified. The study group consisted of 3 men and 1 woman who ranged in age from 33 years to 63 years. The masses were located throughout the pancreas. Tumor sizes ranged from 1.8 cm to 5.7 cm in greatest dimension. Smears from all patients revealed numerous anucleated squamous cells, rare benign nucleated cells, amorphous debris, and an absence of lymphocytes. Mildly atypical mucinous glandular and parakeratotic epithelium were identified in 2 patients, leading to diagnoses of atypical and suspicious for malignancy. Subsequent surgical follow‐up of 3 patients revealed pancreatic LECs. CONCLUSIONS. Pancreatic LECs are extremely rare, and certain cytologic pitfalls may hinder a correct prospective diagnosis. Familiarity with the lesion's clinical and cytologic features may help clinicians arrive at the appropriate prospective diagnosis and, thus, permit conservative management. Cancer (Cancer Cytopathol) 2006. © 2006 American Cancer Society.

Lymphoepithelial Cyst of the Pancreas: A Rare Case Report and Review of Literature

“…Chemical analysis of aspirated cyst fluid has proved to be useful in the differential diagnosis of pancreatic cysts in general, the aspirated fluid from LEC has squamous epithelial lining (to differ from pseudocyst) which is rich in lymphoid cells (to differ from mucinous & malignant cystic lesions) & sometimes it may also contain "cheesy" or "caseous" appearance characteristic of keratinaceous debris (like our case) [35][36][37][38][39][40][41].…”

“…Since the treatment options and the prognosis of these entities is different. In these situations, fine needle aspiration (FNA) of the lesion may be able to suggest the benign nature of the lesion and as a true cyst of the pancreas [35][36][37][38][39][40][41]. Cytological material obtained from LEC reveals nucleated or anucleated squamous epithelial cells, occasional histiocytes and rare lymphocytes, without evidence of neoplastic cells.…”

Pancreatic Lymphoepithelial Cyst Showing Multiple Floating Ball-like Appearances

“…This keratin substance can be determined by EUS-FNA, and this, coupled with a cyst fluid concentration of CEA and CA19-9, is diagnostic to some degree [4,8]. However, this also has several diagnostic pitfalls [4,8].…”

“…This keratin substance can be determined by EUS-FNA, and this, coupled with a cyst fluid concentration of CEA and CA19-9, is diagnostic to some degree [4,8]. However, this also has several diagnostic pitfalls [4,8]. Besides, FNA from pancreatic cystic lesions can rarely cause leaks of the cystic fluid [5,6], which result in severe events such as tumor dissemination and chemical peritonitis.…”

“…Histologically, the pancreatic LEC is covered by a single or stratified squamous epithelium with lymphoid aggregation and/or lymph follicles within its cystic wall, with keratin production in the cyst. Obtaining this keratin component by endoscopic ultrasonography-guided aspiration (EUS-FNA) [4] can provide critical evidence allowing the differentiation of LEC from other pancreatic cystic lesions, but this aspiration can cause severe complications such as chemical peritonitis if the cystic fluid leaks [5]. Therefore, the clinician must be well aware of the characteristic images of the pancreatic LEC.…”