[Concurrence of cytochemical and immune patterns of different cell lines in cases of acute leukemia].

Mixed, bilineal, biclonal and hybrid leukemias are synonymous, differing from biphenotypical ones. Mixed acute leukemia is defined by the coincidence of 1) two cytochemical markers of different lineage, or 2) one of them with more than one opposite immunological marker, or 3) more than one immunological marker opposite to another immunological lineage. Seven cases of mixed acute leukemia are presented, two of which showed posttreatment switching. It is concluded that mixed acute leukemias are associated with a poor prognosis, and therapeutic criteria are defined.