Acute lymphoblastic leukemia with Burkitt cell morphology and cytoplasmic immunoglobulin

A case of acute lymphoblastic leukemia with morphological characteristics of Burkitt's leukemia (L3 morphology) is presented. This patient's lymphoblasts were lacking in surface immunoglobulin, but were found to contain cytoplasmic IgM. This is the first report of a morphologically B-cell leukemia showing pre-B-cell characteristics immunologically.