Double Lineage Switch from Acute Megakaryoblastic Leukemia(AML-M7) to Acute Lymphoblastic Leukemia (ALL) and Back Again: A Case Report

A 39-year-old woman was diagnosed as having immune thrombocytopenia (ITP) in 1981 in another hospital, and she was well controlled with prednisolone. No other immunosuppressive drugs, such as cyclosporine or azathioprine, were used. In 1997, she was diagnosed as having acute megakaryoblastic leukemia (AML-M7) in another hospital. Blasts showed the absence of peroxidase (POX) and positive platelet peroxidase (PPO). She received two cycles of remission induction chemotherapy (cytarabine+idarubicin), but failed to achieve remission. She received supportive therapy, including blood transfusion. In January 1998, cervical lymph node swellings appeared. Bone marrow aspiration showed a dry tap, and peripheral blasts were CD10+, CD19+, and HLA-DR+. Acute lymphoblastic leukemia (ALL) of FAB type L2 was diagnosed in another hospital. She was treated with vincristine and prednisolone and achieved remission.