Cytological and immunological study of 139 patients with acute leukemia.

Sixty-six children with acute lymphatic leukemia (ALL), 26 adults with ALL and 47 adults with acute myeloid leukemia (AML) were subclassified according to the classifications French-American-British (FAB) and World-Health-Organization (WHO). Nine immunological markers and 6 cytochemical stains were also used. The reproducibility of the WHO classification of the smears performed independently twice by one observer was 93%, but that between two observers only 78%. Three patients considered ALL by A were called AML by B, but all three had the common acute leukemia antigen, CALLA. In the group of 87 patients considered ALL by B, only 74 were classified ALL by A, but of the 13 non-ALL B, none had the CALLA. Ten of these thirteen patients had myeloid markers such as Philadelphia chromosomes, peroxidase or Sudan Black B positive reactions, or Fc and C3 receptors. The remaining 3 patients were non-Hodgkin lymphoma with B-cell markers. None of the 47 cases classified as AML had CALLA. Seventeen of nineteen myeloblastic leukemias (M2, FAB) had a myeloid antigen (Mag) and 13 of 15 myelomonocytic leukemias (M4, FAB) had, in addition, Fc and C3 receptors.