Clinical Risk Factors and Outcomes of Spontaneous Hepatoblastoma Rupture in Children: A 10-Year Propensity Score-Matched Study

Background: Spontaneous rupture of hepatoblastoma is uncommon but potentially fatal in children. Published cohorts often combine spontaneous, traumatic, biopsy-related, and treatment-associated events. We aimed to identify clinical risk factors for spontaneous rupture and evaluate its prognostic impact. Methods: We retrospectively reviewed 106 children with pathologically confirmed hepatoblastoma treated at a tertiary center from July 2010 to July 2020. After excluding 10 with incomplete data or follow-up, 96 were eligible. Fourteen children who presented with spontaneous rupture were included in the rupture group. Eighty-two children without rupture were eligible as controls, and 42 were selected after 1:3 propensity score matching for age, sex, height, and weight. Rupture was diagnosed by contrast-enhanced imaging and/or intraoperative findings. Logistic regression was used to identify independent risk factors. Overall survival (OS) and event-free survival (EFS) were estimated using the Kaplan-Meier analysis. Results: The rupture group had lower hemoglobin levels, larger tumors, more frequent bilobar disease, higher PRETEXT stage, and substantially more vascular invasion. In multivariable analysis, maximum tumor diameter (odds ratio 3.078, 95% confidence interval 1.62-5.55; P< 0.001) and vascular invasion (odds ratio 13.521, 95% confidence interval 1.16-148.23; P=0.037) were independently associated with rupture. The combined model incorporating maximum tumor diameter and macrovascular invasion showed an apparent area under the curve of 0.930 and an optimism-corrected area under the curve of 0.924. Children with ruptures had significantly worse OS and EFS than matched controls. Conclusions: Large tumor burden and macrovascular invasion were independently associated with spontaneous hepatoblastoma rupture. Rupture was linked to inferior survival, supporting intensified surveillance and rapid multidisciplinary management for children with these high-risk features.