Abstract: Objective To analyze the clinical features, treatment and prognosis of undifferentiated embryonal sarcoma of the liver (UESL) in children. Methods The clinical data of 8 children with UESL admitted from November 2012 to June 2019 were retrospectively analyzed. Kaplan-Meier survival analysis was used to calculate the survival rate. Result There were 8 children ( 5 boys and 3 girls). The median age of onset was 7 years ( 8 months to 10 years). The tumors of the 8 children were all located in the right lobe of the liver, and the median maximum diameter was 13 . 5 cm ( 10 - 20 cm). Ultrasonography showed intrahepatic solid cystic mass with mixed echogenicity. All patients underwent complete resection of the tumor, and 3 patients had tumor rupture before surgery. Six cycles of alternating chemotherapy were performed between AVCP regimen (cisplatin, vincristine, adriamycin and cyclophosphamide) and IEV regimen (ifosfamide, etoposide and vincristine). The median follow-up time was 47 ( 24 - 90 ) months, 7 children were in complete remission, and 1 died of recurrence. The 5 -year event free survival (EFS) was ( 79 . 25±9 . 31 ) %. Conclusions Preoperative tumor rupture may occur in children with UESL. Complete resection combined with chemotherapy can achieve long-term disease-free survival.

Key words: liver; embryonal; sarcoma; prognosis; child