Diagnostic Utility of CD200 Immunohistochemistry in Distinguishing EBV-Positive Large B-Cell Lymphoma From Classic Hodgkin Lymphoma

Abstract

Abstract Objectives Epstein-Barr virus–positive large B-cell lymphoma (EBV+ LBCL) is a heterogeneous group of diseases that may resemble classic Hodgkin lymphoma (CHL) both morphologically and immunophenotypically. However, these diseases are treated with different therapies and carry distinct prognoses. We examined CD200 expression by immunohistochemistry in EBV+ LBCL and evaluated its diagnostic utility in the differential diagnosis with CHL. Methods CD200 immunohistochemistry was performed on archival material from 20 cases of CHL (11 EBV+, 9 EBV−), 11 cases of EBV+ LBCL, and 10 cases of diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS). Staining pattern and intensity (0-3+ scale) were recorded. Results CD200 positivity was seen in Reed-Sternberg cells in 19 (95%) of 20 cases of CHL, predominantly in a strong (3+, 15/19) and diffuse (>50% of cells, 17/19) pattern. In contrast, CD200 was negative in 8 (73%) of 11 cases of EBV+ LBCL; the 3 positive cases showed 1 to 2+ staining in less than 50% of lesional cells. All cases of DLBCL NOS were negative for CD200. Conclusions CD200 may be a useful immunophenotypic marker in differentiating EBV+ LBCL from CHL, with negative to partial/weak staining favoring a diagnosis of EBV+ LBCL and strong diffuse staining favoring a diagnosis of CHL.