Megakaryoblastic leukemia: the characterization and identification of
megakaryoblasts
T Koike
This article describes three patients with megakaryoblastic leukemia, in
whom the blast cells were identified as megakaryoblasts by the platelet
peroxidase (PPO) reaction. More than 70% of the blasts in these patients
were positive for the PPO reaction. Ultrastructurally, acid phosphatase
activity in the megakaryoblasts was detected in the nuclear envelope, the
endoplasmic reticulum, and in a few granules, but not in the Golgi
cisternae. Some blast cells were identified by immunofluorescence or
immunoalkaline phosphatase, using monoclonal antiplatelet glycoprotein
IIb/IIIa antibody. In one patient, most of the blasts were positive for
anti-HLA-DR monoclonal antibody. The possible order of the appearance of
markers in the maturation of the megakaryocytic cell lineage is postulated,
based on the data from the present cases and those previously reported. PPO
activity appears in very immature cells, which retain Ia-like antigens.
Platelet-specific glycoprotein IIb/IIIa is seen in immature cells that are
only recognized by PPO activity.
Volume 64,
Issue 3,
pp. 683-692,
09/01/1984
Copyright © 1984 by The American Society of Hematology
