Acute promyelocytic leukemia (APL) is rare in children, accounting for 5-7% of all acute myeloid leukemia (AML) cases. This study aimed to review clinical and laboratory characteristics of pediatric APL patients, and to analyze the therapeutic outcomes. Methods: Twenty pediatric patients with APL, diagnosed from January 1998 to April 2016, were retrospectively reviewed. Clinical and laboratory findings were collected, and morphologic, immunophenotypic, cytogenetic and molecular characteristics

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... ere evaluated. Therapeutic outcomes and prognostic factors of patients were analyzed. Results: The number of pediatric APL patients was 20, which was 18.5% of all the cases of AML. The 5-year overall survival (OS) and event-free survival (EFS) were 88.5±7.6% and 83.0±9.0%, respectively. As compared to typical APL patients, patients with microgranular variants (M3v) (n=4, 20%) showed a tendency for a younger age, low white blood cell counts, and a shorter prothrombin time (P=0.045), but their 5-year OS and EFS were not significantly different. Better survival was observed in ATRA plus chemotherapy group both for 5-year OS (100% vs. 60.0±21.9%, P=0.018), and for 5-year EFS (60.0±21.9% vs. 91.7±8.0%, P=0.080) than ATRA only group. Stem cell transplantations were given to 3 patients and they are alive without disease for 8.3-16.5 years of follow-up. One death after relapse, another death in remission and development of secondary leukemia were encountered during the study period. Conclusion: This study analyzed clinical characteristics of pediatric APL and demonstrated very good outcome with the combination of ATRA and chemotherapy.