Definition:

Although malignant tumors of the liver are rare during childhood, hepatoblastoma is the most common liver cancer in children, usually diagnosed during the first 3 years of life. These tumors are thought to arise from hepatic progenitors or hepatoblasts. The most frequent genetic aberrations (70-90%) in hepatoblastoma occur in genes involved in the Wnt signaling pathway. The Wnt signaling pathway is activated often by acquired activating mutations of the beta-catenin (CTNNB1) gene, and less commonly through constitutional mutations of the APC gene or somatic mutations of other genes in the pathway.