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

Abstract

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 transloction 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 precominant in pleomorphic lymphoma.