Approximately two-thirds of primary liver tumors in children are malignant, and they account for 1.1% of all childhood cancers.1 Hepatoblastoma is the most common malignant liver tumor in children, accounting for two-thirds of all pediatric liver cancers.1,292 The incidence rates for hepatoblastoma have steadily increased over time, doubling from 0.8 per million in the 1970s to 1.5 per million in the 1990s and more recently, increasing at a rate of 4.3% annually.1,293 In contrast, the incidence of hepatocellular carcinoma (HCC) has decreased from 0.6 per million to 0.2 per million.1

Hepatoblastoma accounts for over 90% of all malignant liver tumors in children under the age of 5 years, preferentially affecting males and whites.294,295 The median age at presentation is 16 to 18 months.1,294,295 In contrast, HCC affects both sexes equally and accounts for 87% of primary hepatic malignancies in patients 15 to 19 years of age.1,3

The most common risk factors for the development of hepatoblastoma include low birth weight, familial adenomatous polyposis, Gardner syndrome, Beckwith-Wiedemann syndrome, and hemihypertrophy.3,296–298 In two studies, up to 10% of patients with sporadic hepatoblastoma had germline mutations of the APC gene; thus, routine screening of all children with hepatoblastoma remains controversial.296,299,300 Prematurity has been increasingly recognized as a risk factor for the development of hepatoblastoma, and in one Japanese study, hepatoblastoma ...