Diagnostic and clinical implications of lineage fidelity in acute leukemiapatients undergoing allogeneic stem cell transplantation

We report on a series of five acute leukemia patients who have undergone al logeneic bone marrow transplantation. Initially, these patients were classi fied as having biphenotypic leukemia; however, subsequent developments in t he perception of what constitutes lineage fidelity has resulted in controve rsy regarding the diagnosis. Flow cytometry and non-random cytogenetic resu lts have had a major impact on redefining the concept of biphenotypic disea se. In this report we review the diagnostic dilemma associated with definin g acute leukemia linage fidelity as diagnostic techniques evolve. While our unique focus on the treatment of biphenotypic leukemia patients represents a small population, we verify the single most promising therapy where othe rwise the diagnosis is dismal.