Cytologic Features of Lymphoepithelial Cyst of the Pancreas: Two Preoperatively Diagnosed Cases Based on Fine‐Needle Aspiration

Abstract

We describe the cytologic features seen in fine-needle aspiration (FNA) specimens from two cases of preoperatively diagnosed lymphoepithelial cyst (LEC) of the pancreas. Pancreatic LEC is a rare, true cyst of uncertain histogenesis that may clinically and radiologically mimic a pseudocyst or cystic neoplasm. Both our patients were middle-aged men who presented with vague abdominal pain. Computed tomography (CT) of the abdomen revealed a mass in or around the pancreas, and CT-guided percutaneous FNA (patient 1) and endoscopic ultrasound-guided FNA (patient 2) yielded paste-like yellowgray material. Cytologic smears showed numerous anucleated squamous cells in a background of keratinous and amorphous debris. A few benign nucleated squamous cells and plate-like cholesterol crystals were also seen. Unlike LEC of the head and neck region, only rare lymphocytes and histiocytes were present. Pancreatic LEC was diagnosed based on these cytologic findings and was histologically confirmed following cyst enucleation (patient 1) and partial pancreatectomy (patient 2). We conclude that preoperative FNA and recognition of the characteristic cytologic pattern will enable conservative surgical management of pancreatic LEC.

Lymphoepithelial Cyst of the Pancreas

“…Moreover, keratinizing squamous material can be a contamination from the skin during CT-scan-guided FNA or from the oesophageal mucosa during EUS-guided FNA. 37 Intracystic tumor markers are not reliable and can mislead to a diagnosis of malignancy in case of LEC. In this series, 17 patients had elevated intracystic tumor markers.…”

“…Mucinous cells were described in 13 cases. 1,8,37,43,47 Sebaceous differentiation was present in 16 cases. 1,8,11,23,30,60,64 No atypical cell was described unlike some FNA results.…”

Lymphoepithelial Cyst of the Pancreas: Report of a Case

“…[12][13][14] True cysts and cystic neoplasms of the pancreas are both lined by epithelia. An LEC is a true cyst, and the cytology of an LEC typically shows squamous cells, keratinous debris, and lymphoid tissue.…”

Lymphoepithelial Cyst of the Pancreas

“…In 1985, Luchtrath and Schriefers were the first to describe a pancreatic cyst lined by squamous epithelium with surrounding lymphoid tissue. Two years later, Truong et al defined the term lymphoepithelial cyst of the pancreas [7], in a case report of a unilocular pancreatic cyst filled with keratin material and lined by mature, keratinizing squamous epithelium with a surrounding rim of lymphoid tissue. Clinically, the lesion reported by Truong was associated with diarrhea and abdominal pain, both of which promptly disappeared after its removal [8].…”