Importance of Acute Lymphoblastic Leukemia-type Therapy for Bilineal Acute Leukemia.

We examined 3 pediatric patients with bilineal acute leukemia. Patient 1 with B-cell acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) with B-ALL dominance responded well to prednisolone and ALL-type induction therapy. Patients 2 and 3 with T-ALL and AML with AML dominance responded poorly to prednisolone. Patient 2 was resistant to AML-type therapy; patient 3 was resistant to ALL-type induction therapy until day 15. However, all 3 patients eventually achieved complete remission after ALL-type induction therapy. Thus, ALL-type induction therapy should be initiated for bilineal acute leukemia even with AML-dominant, poor prednisolone response, or poor early response features.