Current Evidence Tumors of the hepatobiliary tree in children are more likely to be metastases rather than primary tumors of the liver ( Table 98.6 ) Of the primary tumors, hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the most common ( Fig 98.2 ) HB usually occurs in patients younger than years and is associated with risk factors such as overgrowth syndromes (e.g., Beckwith–Wiedemann), prematurity, and familial adenomatous polyposis (FAP) In contrast, HCC is more common in patients older than years, particularly in children older than 10 years Risk factors include chronic liver injury from inborn errors of metabolism such as tyrosinemia, glycogen storage disease type I, chronic hepatitis, chronic iatrogenic androgen exposure, or cirrhosis for any reason In general, these latter risk factors rarely lead to cancer in childhood