Relapse of acute megakaryocytic leukemia as hepatic myeloid sarcoma after allogeneic haploidentical hematopoietic stem cell transplantation

摘要

A 1-year-old girl was admitted to hospital with fever and petechiae on the lower extremities. Her past medical history was unremarkable. Initial laboratory investigations revealed a white blood cell (WBC) count of 8,300/uL with 15 % myeloblasts, a hemoglobin level of 9.4 g/dL, and a platelet count of 19,000/muL. Bone marrow aspiration revealed that abnormal myeloblasts accounted for 54.5 % of nucleated cells. These cells were positive for CD33, CD36, CD42a, and HLA-DR, leading to a diagnosis of acute megakaryocytic leukemia (AMKL). G-banding analysis revealed a complex karyotype: 54, XX, +2, +6, +7, +7, +8, +19, +19, +21 (2/20), 55, idem, +10 (12/ 20), 56, idem, +10, +14 (1/20) and 46, XX (4/20). The patient entered complete remission (CR) after induction chemotherapy consisting of etoposide (VP-16), cytarabine (Ara-C), and mitoxantrone (MIT) followed by an additional four courses of chemotherapy consisting of VP-16, high-dose AraC, and idarubicin. However, leukemic blasts emerged in the peripheral blood (WBC count: 6,500/muL with 17 % myeloblasts) 1 month after the completion of treatment.