CD20 positivity in classical Hodgkin′s lymphoma: Diagnostic challenge or targeting opportunity

• Main Authors: Barakzai Muhammad, Pervez Shahid
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2009-01-01
• Series: Indian Journal of Pathology and Microbiology
• Subjects: Hodgkin′s lymphoma; immunohistochemistry
• Online Access: http://www.ijpmonline.org/article.asp?issn=0377-4929;year=2009;volume=52;issue=1;spage=6;epage=9;aulast=Barakzai

<b>Background:</b> It is now well established that Hodgkin cells are clonal B cells with a CD30 and CD15 phenotype. However, on immunohistochemistry, in our experience and the experience of others, CD20 positivity in an otherwise typical classical Hodgkin&#x2032;s Lymphoma is not uncommon and if associated with CD15 negativity poses a potential diagnostic trap and is likely to be called B-NHL. <b> Objective: </b> To assess the frequency of B-cell related antigens CD20 and CD79a in classical Hodgkin&#x2032;s Lymphoma. <b> Materials and Methods: </b> A total of 91 consecutive cases of classical Hodgkin&#x2032;s Lymphoma were analyzed for co-expression of CD20 and CD79a. Both males and females of all ages were included in this study. All cases of nodular lymphocyte predominant Hodgkin&#x2032;s Lymphoma were excluded. All the cases were stained with a panel of antibodies including LCA, CD20, CD79a, CD30, CD15, CD3, EMA and Alk. Protein. <b> Results: </b> All 91 cases of classical Hodgkin&#x2032;s Lymphoma showed negativity for LCA and positivity for CD30. Eighteen cases (19.8&#x0025;) showed distinct membrane staining with CD20 in most of the large atypical cells. However, out of these, only 7 cases (7.7&#x0025;) showed CD79a co-expression, which was largely focal. CD15 negativity with CD20 positivity was seen in 7 (7.7&#x0025;) cases of otherwise typical classical Hodgkin&#x2032;s Lymphoma. <b> Conclusions/Recommendations:</b> CD20 expression is frequent in classical Hodgkin&#x2032;s Lymphoma and our results are in consensus with reported literature on this subject. In these cases, LCA negativity of large cells was extremely useful in clinching the right diagnosis.