Relationship between Epstein-Barr virus and lymphoepithelioma-like carcinoma of the lung: a clinicopathologic study of 6 cases and review of the literature.

Lymphoepithelioma-like carcinoma (LELC) is a rare form of lung cancer, usually encountered in Chinese patients. Similar to nasopharyngeal carcinoma, LELC of the lung is strongly associated with Epstein-Barr virus (EBV) infection in Asian patients, but there is controversy over whether an association exists in patients from Western countries. To determine whether such a relationship exists, we retrospectively studied 6 cases of primary LELC of the lung, all of which were in Western patients. There were 4 men and 2 women, ranging in age from 49 to 75 years. The tumors ranged from 1 to 4.5 cm in diameter. Four patients had stage I disease, 1 had stage IIb disease, and 1 had stage IIIa disease. All patients are alive without evidence of disease with a follow-up of 18 to 30 months. Formalin-fixed, paraffin-embedded tissue was stained with hematoxylin-eosin for routine evaluation and immunostained for keratin and leukocyte common antigen (LCA). LCA staining was performed to exclude large-cell lymphoma. Immunoperoxidase staining (1:500 clone CS1-4; Dako, Carpinteria, CA) and in situ hybridization were performed to detect EBV. Tumors consisted of solid nests of undifferentiated tumor cells in a syncytial arrangement surrounded by heavy lymphoplasmacytic infiltrate. Tumor cells stained positively for keratin but negative for LCA. All 6 cases were negative for EBV, suggesting no association between EBV and LELC in the Western population.