Karyotype evolution in B-cell lymphoid malignancy with an 8;14 translocation

Non-random chromosomal rearrangements and their implications in clinical features and outcome of multiple myeloma and plasma cell leukemia

Rearrangements of bands 14q32.3 and 19p13.3 and preferential deletion of the short arm of chromosome 1 were nonrandom chromosomal abnormalities in MM and PCL, warranting further investigation at the molecular level. From the viewpoint of clinical relevance, chromosome 14q32 translocation seems to be associated with leukemic manifestation, level of LDH, and shorter survival period from the time of chromosomal analysis. However, these results were obtained from patients with advanced disease, most of whom had already been treated with alkylating agents prior to cytogenetic analysis. To investigate the karyotypes of MM in the early stage and to determine correlations with clinical features, non-dividing cells should be analyzed. For this purpose, interphase FISH and/or comparative genomic hybridization are promising procedures to detect genomic alterations in early multiple myeloma.

Nonrandom additional chromosome changes in acute nonlymphocytic leukemia with inv(16)(p13q22)

Five patients with acute nonlymphocytic leukemia and inv(16)(p13q22), all with additional chromosome changes, are reported. Three were diagnosed as having acute myelomonocytic leukemia (FAB-M4), and the other two as having acute monocytic leukemia (FAB-M5b). All five patients had abnormal eosinophils in the bone marrow at diagnosis. Two had a deletion of the long arm of chromosome #7, del(7)(q31), and a trisomy of chromosome #22. These changes have been reported frequently in acute nonlymphocytic leukemia with inv(16), but are extremely rare in leukemias with other specific rearrangements including t(9;22), t(8;21), and t(15;17). Our findings and review of the literature indicate that inv(16) is observed not only in acute myelomonocytic leukemia but also in acute monocytic leukemia, and that del(7q) and +22 are nonrandomly associated with inv(16) as additional abnormalities. No significant differences in the clinical features seem to exist between the patients with only inv(16) and those with inv(16) and additional chromosome changes, except for the lower white blood cell count in the latter group.

Recurrent chromosome abnormalities in adult T-cell lymphomas of peripheral T-cell origin

Cytogenetic studies were performed on 11 Japanese patients with adult T-cell lymphoma of peripheral T-cell origin. All patients had a histologic diagnosis of diffuse lymphoma, and were treated with intensive combination chemotherapy; their median survival was 6 months. Lymphomas were categorized on the basis of the classification proposed by the Lymphoma Study Group of Japan: 5 patients had the features of pleomorphic lymphoma; 3, mixed lymphoma; 2, large-cell lymphoma; and 1, medium-sized-cell lymphoma. The modal chromosome number of abnormal cells was near-diploid in 7, and hypotetraploid in 4 including 3 patients with pleomorphic lymphoma. Abnormalities of the clonal chromosomes were observed in all 11 patients. A translocation of the short arm of 19 at band 19p13 was found in 2 patients with pleomorphic lymphoma and in one patient each with mixed lymphoma and medium-sized-cell lymphoma. A translocation of the short arm of 14, with a break at band 14p12, occurred in 4 patients with pleomorphic lymphoma. In one patient each with mixed lymphoma and large-cell lymphoma, an extra chromosome 3 was found. The numerical change was unique because their lymphomas were further categorized as "angioimmunoblastic lymphadenopathy with dysproteinemia" and "large-cell immunoblastic lymphoma", respectively. Our findings suggest that characteristic chromosome abnormalities occur in adult T-cell lymphoma, and dividing cells in the tetraploid range tend to be predominant in pleomorphic lymphoma.