Abstract
Cytogenetic, pathologic, and immunologic studies were done on 10 patients with lymphoblastic lymphoma (LL). The median age was 21 years, and males predominated in a ratio of 9:1. At the time of diagnosis, 6 of the 10 patients had an anterior mediastinal mass, 3 had bone marrow involvement, and 2 had central nervous system involvement. All patients were treated with intensive combination chemotherapy. The median survival of the 8 patients who died (7 of whom were adults) was 10.5 months; all 8 achieved only a partial remission. Two other patients were children; they continue in complete remission. Immunologic marker studies were done on 9 of the patients; 5 had Tβcell LL, and the other 4 had nonβT, nonβB LL. In a study of Tβcell subpopulations with the use of monoclonal antibodies, the malignant T cells of the 2 patients tested appeared to be mature thymocytes. Clonal chromosome abnormalities were seen in involved tissues from 8 patients; the other 2 patients had a normal karyotype. A 9q+ chromosome, a 6qβchromosome, and a 1qβchromosome associated with 1q trisomy were each seen in 2 patients. No patient had a 14q+ chromosome, which is the most common abnormality in various lymphoproliferative disorders, including other Tβcell malignant diseases. The variable chromosome pattern in LL could be related to the heterogeneity of the immunologic phenotype of the malignant T cells. More data are needed before it can be established whether there are any correlations between a particular karyotype and the immunologic phenotype of LL cells.