HETEROGENEITY OF CELL LINEAGES IN L3 LEUKEMIAS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 55  (4) , 694-698
Abstract
Five cases of adult leukemia with L3 morphology in bone marrow were studied for the presence of immunologic, metabolic and enzymatic markers. Among the 5 patients, there were 4 males and 1 female. Median age was 66 with a range of 16-80 yr. Median survival was only 5 mo. Serum lactate dehydrogenase (LDH) levels, 3H-thymidine labeling indices and DNA/RNA content of the L3 lymphoblasts were markedly elevated. B[bone marrow-derived]-cell markers were found in 3 cases, 2 exhibiting surface membrane Ig[immunoglobulin]M-.lambda., and one IgG-.KAPPA.. Terminal deoxynucleotidyl transferase (TdT) enzymatic activity was consistently low in this group. In 1 case, the L3 lymphoblasts displayed only surface Fc receptors demonstrated by the binding of aggregated IgG. TdT activity was significantly increased. In another instance, the lymphoblasts formed spontaneous rosettes with sheep erythrocytes and exhibited paranuclear staining with acid phosphatase. TdT activity was low. Although most of the L3 leukemias are neoplasias of B lymphocytes, other lineages may also express this morphology.