Case Report: Hepatoblastoma with spindle cell sarcomatous metastasis in a 14-year-old girl.

Hepatoblastoma (HB) is the most common pediatric liver malignancy and occurs predominantly in children younger than 5 years of age. We report the case of a 14-year-old girl who was diagnosed with mixed epithelial-mesenchymal hepatoblastoma without any metastases. Initial evaluation revealed a markedly elevated serum alpha-fetoprotein level (7,800 ng/mL) and a large hepatic mass (17.3 cm × 18.4 cm × 8.5 cm) in the left liver lobe on contrast-enhanced CT. The patient underwent surgical resection, and pathological examination confirmed mixed epithelial-mesenchymal HB. Postoperative chemotherapy (consisting of cisplatin, doxorubicin, and 5-FU) normalized serum alpha-fetoprotein levels; however, skull metastasis developed during treatment. Histopathological analysis of the metastatic lesion revealed spindle cell sarcoma with decreased GPC-3/Hepa expression and elevated CD34/Ki-67 expression. Multiple chemotherapy regimens (ifosfamide, carboplatin, and etoposide; and doxorubicin, vincristine, cyclophosphamide, and cisplatin) demonstrated limited efficacy. Subsequent treatment with alternating albumin-paclitaxel, gemcitabine, ifosfamide, and etoposide/cyclophosphamide, irinotecan, and vincristine chemotherapy combined with anlotinib and cranial radiotherapy achieved disease stabilization, with no subsequent progression observed during follow-up. This case highlights the aggressive nature and chemoresistance of the mesenchymal components of HB, emphasizing the need for novel therapeutic approaches that incorporate targeted agents.