A Case Report of Lymphoepithelial Cyst: The Great Imitator of Pancreatic Malignancy

Abstract

There is a variety of pancreatic cysts which can be divided into neoplastic and non-neoplastic. Excluding inflammatory fluid collections secondary to acute pancreatitis, non-neoplastic pancreatic cysts (NNPC) are uncommon. Here we describe an extremely rare case of a female patient presenting with lymphoepithelial cyst (LEC) which primarily occur in males. Patient is a 61 year old Dominican female with past medical history of hypertension and dyslipidemia who presented to our institution complaining of 1 month history of epigastric pain radiating to her back and 20 pounds weight loss. She did not pay attention to this at first, however, pain got progressively worse and she went to see a primary care physician who scheduled patient for imaging and EGD. As pain increased to a point that she was unable to sleep at night, patient's daughter decided to take her to emergency department prior to further evaluation. She denied any tobacco or alcohol use. CT of abdomen/pelvis with PO/IV contrast was obtained and found a 5.1 cm focal lesion within body and tail of pancreas with mild peripancreatic stranding without evidence of a fluid collection, and atrophy of distal tail with multiple small cysts which may represent dilatation of pancreatic duct. Abdominal MRI with and without contrast was consequently obtained which showed a 5.1 x 2.1 x 4.0 cm heterogeneous cystic/necrotic mass within body of pancreas; ductal dilatation in tail up to 3.8 mm; and abutment of splenic artery and possible occlusion of splenic vein resulting in varices within left upper and mid abdomen. Labs were unremarkable except for CA19-9 of 197 and CEA of 6.9. EUS with FNA was then performed which identified a 5.0 x 4.0 x 3.5 cm hypoechoic, heterogeneous lesion in body and tail of the pancreas. Rapid on-site evaluation was performed with finding suspicious for LEC. Subsequent smears and cell block revealed numerous lymphocytes and squamous cells favoring lymphoepithelial cyst. Patient was referred to hepatobiliary surgery for further evaluation and scheduled for open distal pancreatectomy. EUS with FNA is the modality of choice for diagnosis of LECs and other NNPCs. Although high tumor markers have been reported in LECs, there is no literature describing malignant transformation. Therefore, it is imperative to correctly characterize cystic pancreatic lesions, as NNPCs can mimic neoplastic process but would only require surgical treatment if symptomatic.FigureFigure