Pediatric Ewing Sarcoma as Secondary Malignancy Following Hepatoblastoma: A Case Report and Literature Review

Background: Due to the markedly improved long-term survival of pediatric cancer patients, secondary malignant neoplasms are being increasingly detected during follow-up. This report presents the rare case of a male patient who developed Ewing sarcoma 10.5 years after successful treatment of primary hepatoblastoma, one of only four cases reported in the literature. The diagnosis was complicated by initial misidentification as a metastatic recurrence of hepatoblastoma, further hindered by a noncontributive biopsy, highlighting significant diagnostic challenges and the critical need for advanced molecular techniques. Case presentation: Our patient is a Caucasian male who was diagnosed with hepatoblastoma at the age of 3.6 years. He was successfully treated using both surgery and chemotherapy, receiving a cumulative anthracycline dose of 300 mg/m². After a decade of remission, he developed Ewing sarcoma of the left femur. In light of his previous exposure to cardiotoxic agents, a modified Euro Ewing 2012 chemotherapy protocol was employed, substituting doxorubicin with dactinomycin. Conclusions: The current review revealed no definitive correlation between genetic or therapeutic factors, such as radiotherapy or specific chemotherapy agents, and an increased predisposition to developing secondary Ewing sarcoma.