The most common chromosome change in 86 chronic B cell or T cell tumors: a 14q32 translocation.

Among 46 patients with chronic lymphocytic leukemia (CLL) (40 B cell, 6 T cell) and 40 patients with cutaneous T cell lymphoma (CTCL), a chromosomally abnormal neoplastic clone was identified in 43 cases. A translocation involving 14q32 was present in nine cases (five B-CLL, two T-CLL, two CTCL). The donor chromosomal site was 11q13 in four patients and 1q12, 4q25-27, 17q21-22, 18q21, and 22q11 in one case each. The next most frequent abnormalities were rearrangements involving 6q21-23 (four cases), and trisomy 12 (four cases, all B-CLL). In one CTCL patient, the t(11;14) translocation was present in one of three apparently unrelated T cell clones. Recent studies indicate that the selective advantage conferred by the 14q+ chromosome in B cell neoplasms appears to result from an oncogene being brought adjacent to a rearranged and transcriptionally active immunoglobulin heavy chain locus. The present findings suggest that similar mechanisms may operate in certain T cell neoplasms, although the activating gene is not necessarily the same.