[Cytochemical evaluation of blast cells in acute myeloblastic leukemia after induction of their maturation in liquid culture--diagnostic usefulness].

We have performed the cytochemical analysis (myeloperoxidase, ASD-chloroacetate and acid alpha-naphthylacetate esterases, Sudan black B) of blast cells from 25 acute leukemia patients, after 3, 5 and 7 days of liquid culture with conditioned medium from phytohemagglutinin stimulated leukocytes (PHA-LCM). In case of acute myeloid leukemia blast cells an increase of percentage of positive cells simultaneously with the enhancement of the cytochemical reactions was observed. This method may be useful for the precise diagnosis of poorly differentiated blasts with weak expression of cytochemical phenotype.