We studied 24 anaplastic large cell lymphomas (ALCL) classified by World Health Organization criteria [17 primary nodal/systemic (10 ALK+, 7 ALK-), seven primary cutaneous], and 17 additional non-Hodgkin's lymphomas [one ALK+ B-lineage lymphoma, 14 ALK- diffuse large B-cell lymphomas (seven anaplastic variants, five nonanaplastic, two secondary CD30+), two follicular lymphomas].