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.
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.