Some recurrent chromosomal abnormalities have recently been found to be associated with distinctive histologic subtypes of non-Hodgkin's lymphoma (NHL). In a study of 62 patients with NHL whose karyotypes was determined at diagnosis, 3 patients were found to have a deletion of the long arm of chromosomes 14 at band 22 (del[14][q22]). All had a diffuse lymphoma with generalized lymphadenopathy and bone marrow involvement. All three lymphomas were of B-cell origin, as shown by the presence of surface immunoglobulin and monoclonal antibody phenotyping. For each patient, a trisomy 12 was associated with del(14)(q22) in a clone. These data suggest that del(14)(q22), perhaps in association with trisomy 12, could identify a subtype of NHL and that band 22 of chromosome 14 may be implicated in the B-cell ontogeny.