Undifferentiated embryonal sarcoma of the liver in pediatric patients: a single-institution retrospective case series.

Background: Undifferentiated embryonal sarcoma of the liver (UESL) is a rare and highly aggressive malignancy predominantly affecting children and adolescents. Managing UESL is particularly intricate due to its aggressive nature and the limited array of treatment options available. This study is dedicated to elucidating the efficacy of a multimodal therapeutic strategy in the successful management of UESL. Case Description: Four pediatric patients (two males, two females; aged 6-11 years) diagnosed with UESL were treated at the Children's Hospital of Nanjing Medical University between November 2019 and June 2023. Surgical resection with lymph node dissection achieved complete primary tumor eradication. Adjuvant chemotherapy tailored to each patient's needs was followed by localized radiation therapy. After 9-42 months of follow-up, one patient who did not undergo immediate radiotherapy experienced a relapse. Following a second operation coupled with radiotherapy, the patient achieved complete remission, and mirroring the status of the other three patients who are now presently in remission. The overall cohort exhibited commendable tolerance to the treatment regimen, with manageable chemotherapy-related toxicities. Conclusions: This case series suggests that implementing a standardized protocol of resection, followed by adjuvant chemotherapy and radiation, can lead to favorable outcomes in pediatric patients diagnosed with UESL. Nevertheless, the need for comprehensive large-scale studies is imperative to substantiate the effectiveness of this approach.