A child who had acute lymphoblastic leukemia (ALL) associated with an 8;14 chromosome translocation and with a pre-B phenotype is described. The leukemic cells were determined to be pre-B cells on the basis of intracytoplasmic .mu.-chain immunoglobulin (cIgM+) and the common-ALL antigen, lack of receptors for sheep erythrocytes, and lack of surface immunoglobulin. The 8;14 translocation is frequently found in patients with Burkitt''s lymphoma and in most patients with B-cell ALL and is known to carry a poor prognosis. Thus far, no karyotypes have been reported for patients with pre-B ALL. A 14q+ chromosome may provide a proliferative advantage not only to cells with a B-cell phenotype, but also to pre-B cells. The short survival of the patient also suggests that the 14q+ abnormality and the pre-B phenotype may signal a poor prognosis.