Objective: To study the clinical, biological features and prognosis of acute biphenotypic leukemia (BAL) in the adults.
Methods: Bone marrow specimens of 63 BAL patients were evaluated to prove the diagnosis and the classification by morphologic, cytochemical, immunologic and cytogenetic (MIC) examinations. These patients were treated with protocols suitable for acute myeloid leukemia (AML), or acute lymphoblastic leukemia (ALL), or both.
Results: No significant difference in clinical features was observed between BAL, AML or ALL. Morphologically, the subtypes of M(5), M(1) and M(2) were predominant in AML, as L(2) and L(1) were in ALL. Immunologically, coexpression of myeloid and B lineage associated antigens was predominant and CD(34) was hyperexpressed in BAL, which suggested that BAL might originate from malignant transformation of earlier hematopoietic cells. Cytogenetically, Ph chromosome was observed in 25.5% (13/51) of BAL patients. Prognostically, both the treatment response and the overall survival of BAL patients were poor.
Conclusion: Patients with BAL have unique clinical, biological and prognostic features.