CD30 expression in follicular lymphoma.

The CD30 antigen is a characteristic phenotypic feature of Sternberg-Reed and Hodgkin cells and is also found in a subset of large cell non-Hodgkin's lymphomas. The finding of CD30 positive cells in some centroblastic/centrocytic (cb/cc) follicular lymphomas prompted us to characterize the presence and distribution of CD30 positive cells in this type of lymphoma, using the monoclonal antibody BerH2. CD30 positive cells were present in 17/19 of the cases studied, located mainly at the edge of the neoplastic follicles, but also in some cases in perinodular or T-cell areas. This distribution resembles that found in reactive tonsils and lymph nodes. The majority of these CD30 positive cells in cb/cc lymphoma seem to be B-cells, as suggested by their reactivity with B-cell markers demonstrated by double immunostaining. The nature of these CD30 positive cells is unclear, but they should be taken into consideration in the differential diagnosis of cb/cc lymphoma with lymphocyte predominance Hodgkin's disease.