CD30 expression in non‐Hodgkin's lymphoma

The CD30 antigen has been reported as the immunophenotypic hallmark of a recently described category of non‐Hodgkin's lymphoma, termed anaplastic large cell lymphoma. From a series of approximately 500 lymphomas, 17 cases showing typical anaplastic features have been identified. They were strongly labelled by monoclonal antibodies recognizing CD30 (Ki‐1 or BerH2). However, 36 other lymphomas, mainly high‐grade, of non‐anaplastic cytology also expressed CD30, either diffusely or focally, with a staining pattern identical to that seen in anaplastic large cell lymphomas. This clearly suggests that such lymphomas cannot be identified solely on the basis of being high‐grade non‐Hodgkin's lymphomas showing CD30 positivity. From the present results, the distinction between the anaplastic and non‐anaplastic types would be better made with antibodies to epithelial membrane antigen than to CD30. Clinical data, available for 48 of the patients (16 with anaplastic large cell lymphomas and 32 with non‐anaplastic) revealed no significant differences with regard to age at presentation, sex or clinical signs. A short‐term follow‐up study of 25 patients revealed that for the first 2 years after diagnosis there were no significant differences in patient survival between anaplastic large cell lymphoma, other CD30+ high‐grade lymphomas and all high‐grade non‐Hodgkin's lymphomas considered together. These findings, which must be confirmed by larger studies, suggest that in a general lymphoma clinic there is probably little justification for differentiating anaplastic large cell lymphomas or CD30+ lymphomas from other high‐grade non‐Hodgkin's lymphomas.