VOL3, NO5 Annals of DIAGNOSTIC PATHOLOGY OCTOBER 1999 ORIGINALARTICLES Hodgkin's and Non-Hodgkin's Lymphoma: Spectrum of Morphologic and Immunophenotypic Overlap John Elgin, MD, J. GregoryPhillips, MD, Vishnu V.B. Reddy, MD, Patty O. Gibbs, HT (ASCP), and Catherine M. Listinsky, MD Immunoperoxidase markers are useful and often essential in distinguishing among lymphocyte-predominant Hodgkin's lymphoma, T-cell-rich B-ceB lymphoma, and lymphocyte-rich classic Hodgkin's lymphoma. However, it is becoming increasingly clear that these "entities" are closely related clonal B-lineage neoplasms that may intertransform and/or coexist. We hypothesized that, just as there are cases with morphologic overlap, there would also be immunophenotypic overlap that would be found when a series of such cases is studied in detail. Eight cases of lymphocyte predominant Hodgkin's lymphoma, eight cases of lymphocyte-rich classic Hodgkin's lymphoma, seven cases of T-cell-rich B-cell lymphoma, and four cases of large B-cell lymphoma with focal features of T-cell-rich B-cell lymphoma were examined by the immunoperoxidase technique for expression of CD3, CD15, CD30, CD20, CD57, epithelial membrane antigen, and Epstein-Barr virus latent membrane protein (EBV LMP). All eight of the lymphocyte-predominant Hodgkin's lymphoma cases had CD20 + lymphocytic and histiocytic ceils and CD57+ rosettes; however, in two cases, occasional lymphocytic and histiocytic cells were also weakly positive for CD15, CD30, and EBV LMP. Among the eight lymphocyte-rich classic Hodgkin's lymphoma cases, CD15+ Reed-Sternberg (R-S) cells were found in seven; however, in three of these cases rare rosettes of CD57+ cells surrounded the R-S or lacunar cells. In one case of large B-cell lymphoma the malignant cells resembled R-S cells and were CD20+, EBV LMP+, CD30+, CD15-, and surrounded by rosettes of CD57+ T cells. The majority of the cases exhibited the "expected" immunopheno- typic patterns; however, the exceptional cases that were found serve to confirm the interrelationship among these clonal B-lineage neoplasms. Ann Diagn Pathol 3: 263-275, 1999. Copyright © 1999 by W.B. Saunders Company Index Words: Hodgkin's disease, non-Hodgkin's lymphoma, T-cell-rich B-cell lym- phoma, composite lymphoma,immunophenotype ITHLN the last few"years our understanding of odgkin's l~anphoma and its relationship to the non-Hodgkin's lymphomas has greatly improved, From the Departmentof Pathology,RussellHospital, Alexander City, AL; Cunni@am Pathology Associates,Birmingham,AL; DepartmentofPathology and Laborato{y Medicine, University of Alabama at Birmingham"and Cytology &Pathology Services, h~c, Birmi@am, AL. Address reprint requests to CatherbwM. Listinsky, MD, Department of Pathology, University of Alabama at Bimzingham, 619 S 19thSt, Birmingham, AL 35233-7331. Copyright© 1999by I/KB. SaundersCompany 1092-9134/99/0305-0001310.00/0 through studies of composite and sequential malignan- cies, I through the development of a variety of immu- noperoxidase markers that can be used in paraffin- embedded tissues, and through sophisticated molecular biologic techniques which have shown that both nodular lymphocyte predominant Hodgkin's lymphoma 2-5 and most cases of classical Hodgkin's lymphoma~ are clonal neoplasms of B lineage. In clinical diagnostic practice, l~Tnphocyte-predomi- nant Hodgkin's lymphoma, classic Hodgkin's lym- phoma, and non-Hodgkin's lymphoma can often be distinguished from each other by their characteristic Annals of Diagnostic Pathology, Vol 3, No 5 (October), 1999: pp 263-275 263