Acute lymphoblastic leukemia with Burkitt's lymphoma cells: membrane markers and serum immunoglobulin.

Blast cells from 24 patients with acute lymphoblastic leukemia of Burkitt's cell type were studied for lymphocyte surface markers. The leukemia cells were of B-cell origin in 23 cases and showed a non-B, non-T phenotype in 1 case. Surface immunoglobulins on blast cells were monoclonal, with a striking predominance of cases with light chains of lambda type. They consisted most often of high-density IgM usually without associated IgD. However, 3 patients had cells with surface IgG and 1 had surface IgA. The blast cells lacked detectable IgG Fc receptors in more than half the patients. Serum immunoglobulins were studied in 15 cases: A monoclonal IgM was found in 5 patients (whose blast cells had surface IgM) and a Bence Jones protein was found in 2 others, both of whom had blasts with surface IgG lambda.