Epstein-Barr Virus-associated Gastric Lymphoepithelioma Like Carcinoma

Abstract

Case Presentation: A 69-year-old female presented with a six-month history of intermittent epigastric pain associated with 15-pound weight loss. She denied any past medical or surgical history. Physical exam was benign but her lab results were significant for microcytic anemia. Computed tomography (CT) of the abdomen with oral contrast demonstrated thickening of the anterior and posterior walls of the body and antrum of the stomach. Upper endoscopy revealed a large, friable, ulcerated, malignant-appearing mass in the antrum. Biopsy indicated invasive gastric adenocarcinoma, poorly differentiated with ulceration. The patient underwent a subtotal distal gastrectomy with gastrojejunostomy, followed by radiation therapy. Pathologic findings of the resected stomach showed a well demarcated tumor with raised border and central shallow ulcer in the antrum extending to and involving the lesser curvature, partially involving but not obstructing the pylorus. Microscopically, an undifferentiated carcinoma with intense lymphoid infiltration, invading through muscularis propria and subserosal connective tissue was detected. The tumor cells were polygonal with pale eosinophilic cytoplasm. Carcinoma cells stained strongly positive for both EBV and cytokeratin. CD3 was positive, evenly distributed throughout the tumor with intimate contact with individual carcinoma cells. CD20 was positive, sparsely scattered within the tumor. Three out of 15 lymph nodes along the lesser curvature were positive for metastatic carcinoma with lymphovascular invasion. The case was diagnosed as a gastric lymphoepithelioma-like carcinoma and the pathologic staging was T3N2M0 or UICC/AJCC Stage IIIb. Surveillance endoscopy performed two months post gastrectomy revealed chronic gastritis; however, no tumor was detected. No positron emission tomography evidence of metastatic spread of tumor was observed. Discussion: Lymphoepithelioma-like carcinoma (LELC) is a descriptive term for poorly differentiated carcinoma accompanied by prominent infiltration of lymphocytes; notably seen in nasopharyngeal and gastric carcinomas. Lymphoepithelioma-like gastric carcinoma is a rare neoplasm of the stomach most often seen in males, with a better prognosis than conventional adenocarcinoma. More than 80% of gastric LELC have been found to be related to EBV infection. EBV associated LELC is associated with 4-16% of gastric adenomas, with variations across populations. Even rarer is EBV associated LELC with lymph node metastasis. Fortunately for our patient, surveillance endoscopy has been negative for malignancy, to date.