Abstract: Objective　To investigate the clinical characteristics and prognosis of acute leukemia after treatment for hemophagocytic lymphohistiocytosis (HLH). Methods Clinical data of two cases with acquired EBV-triggered HLH with progression to acute leukemia following chemotherapy was analyzed, and 13 cases of secondary acute leukemia (sAL) following the treatment of HLH in the literature were reviewed. Results　Two male cases with acquired EBV-triggered HLH (EBV-HLH) were treated with HLH-2004 regimen. The cumulative dose of etoposide was 1500 mg/m2 and 3900 mg/m2, respectively. One child developed acute promyelocytic leukemia (APL) 18 months after the first chemotherapy regimen, and achieved complete remission (CR) after induction chemotherapy with retinoic acid and daunorubicin. Then he received regular chemotherapy, and continued CR was observed after following up for 30 months. Another patient developed acute mononuclear leukemia (M5) 50 months after the first chemotherapy, who reached CR after AML chemotherapy. However, he relapsed 9 months after withdrawal and reached CR after hematopoietic stem cell transplantation. Following up for 12 months, the patient got continued CR. Thirteen cases of sAL following chemotherapy for HLH were reported. Of the 15 cases, 10 were male and 5 were female. The median age was 2 years and 6 months old (4 months to 19 years old). The cumulative dose of VP16 was 3900 mg/m2 (400-20975). The median interval between HLH and secondary leukemia was 24 months (6-72). The types of secondary leukemia included M3 in 5 cases who received chemotherapy and survived without disease, and other types of AL in 10 cases, in which 3 cases received chemotherapy (1 case died and 2 cases were unknown), 6 cases were performed hematopoietic stem cell transplantation ( 3 cases survived and 3 cases died) , and 1 case gave up treatment after suffering from AL. Conclusions　Most of the acute leukemia secondary to HLH are AML. APL has a good prognosis treated with retinoic acid-based combination chemotherapy, while other types have a poor prognosis. Hematopoietic stem cell transplantation may improve the prognosis.

Key words: lymphohistiocytosis;　hemophagocytic;　leukemia ;　 Etoposide