Abstract: Background：At present, there are few reports about acute leukemia in children with peripheral facial paralysis as the initial symptom, and it is easy to be misdiagnosed clinically. Objective：To investigate the clinical characteristics，treatment and prognosis of children diagnosed with acute leukemia presented with peripheral facial paralysis as the initial symptom. Design：Case series report. Methods：The children diagnosed with acute leukemia presented with peripheral facial paralysis as the initial symptom admitted to the Department of Pediatrics of Peking University People's Hospital from January 2010 to September 2021 were included. The clinical characteristics, laboratory examinations, treatment and outcome were analyzed. Main outcome measures：The outcome of facial paralysis，5year eventfree survival（EFS），overall survival（OS）. Results：A total of 1 018 children with acute leukemia were admitted during the study period, including 728 patients with ALL and 290 patients with AML. Sixteen children(1.6%) presented with peripheral facial paralysis as the initial symptom, including 7 males and 9 females, with a median age of 5 years (214 years), and a median time from onset of facial paralysis to diagnosis of facial paralysis was 9.5 days(131 days).There were 2 cases （12.5%) of Bcell leukemia, 1 case(6.2%) of Tcell leukemia and 13 cases(81.3%) of M2 myeloid leukemia. All 16 patients had unilateral leukemia, 5（31.2%）were left and 11（68.8%）were right. 15 cases underwent head MR examination, 2 cases showed dural and leptomeningeal thickening and enhancement (including 1 case with suspicious facial nerve injury), 1 case showed leukemia infiltration of medial rectus muscle and orbital segment of optic nerve, and 3 cases showed mastoiditis.Cerebrospinal fluid(CSF) was examined in 15 cases, of which 1 case had CSF minimal residual positive and transient elevation of CSF protein occurred in 1 case. One patient gave up treatment after leukemia diagnosis, and the other 15 patients received chemotherapy. Eight patients remains continuous remission with regular chemotherapy，6 patients received hematopoietic stem cell transplantation, and 1 patient died after relapse due to multiple organ dysfunction during chemotherapy. The symptoms of facial paralysis disappeared in 13 cases within 1 month, and in 2 case within 3 months. The median followup time was 44.5(0.23111) months，the 5year eventfree survival(EFS) was(48.2±13.0)％，and 5year overall survival(OS) was (87.5±8.3)％．The 5year EFS and 5year OS of 13 AML children were (51.3±14.6) % and (84.6±10.0) %, respectively, with 5year OS 100% in the transplant patients and (87.5±11.7) % in the onlychemotherapy patients, showing no statistical difference (P=0.48). Conclusion：Peripheral facial paralysis as the initial symptom of childhood acute leukemia is likely to be misdiagnosed. For children with peripheral facial paralysis, comprehensive examination should be completed to exclude secondary causes before steroid therapy. Intensive central nervous system therapy should be considered in children with acute leukemia with facial paralysis. The overall survival rate of AML children with facial paralysis was not significantly affected, but they were more likely to relapse.

Key words: Peripheral facial paralysis, Children, Leukemia