The frequency of Epstein-Barr virus (EBV) in
anaplastic large cell lymphoma (ALCL) has been controversial. The interpretation of previous studies is complicated by the use of nonuniform EBV detection methods and the inclusion of cases of CD30-positive
diffuse large B-cell lymphoma and so-called "ALCL, Hodgkin-like," as defined in the Revised European-American
Lymphoma classification scheme. In the current World Health Organization (WHO) classification system, both of these
tumors are excluded from the ALCL category. Also, recently developed
antibodies (eg, the antibody specific for PAX-5/
B-cell-specific activator protein [BSAP]) provide new, sensitive tools for identifying
neoplasms of B-cell lineage that can morphologically resemble ALCL. In this study we evaluated 64 cases of ALCL of T- or null-cell lineage, defined according to the WHO classification system, for the presence of EBV. All
tumors were negative for B-cell
antigens, including PAX-5/BSAP and CD20 or CD79a. The study group included 27 (42%)
anaplastic lymphoma kinase (ALK)-positive (18 T-cell and 9 null-cell) and 37 (58%) ALK-negative (30 T-cell and 7 null-cell)
tumors analyzed by in situ hybridization for EBV-encoded
RNA (EBER) or immunohistochemistry for EBV-latent
membrane protein type 1. All 64 cases were negative for EBV. We conclude, based on the current definition of ALCL in the WHO classification, there is no role for EBV in ALCL arising in Western patients. We suggest that published reports of EBV in a small proportion of ALCL cases in Western patients can be explained by the inclusion of
tumors no longer considered to be in the current classification of ALCL, such as CD30-positive anaplastic
tumors of B-cell origin.