hepatoblastoma
Meaning of hepatoblastoma: A tumor of immature liver tissue in very young children, and among the more treatable childhood cancers when caught early.
Definition of hepatoblastoma
Hepatoblastoma is a malignant liver tumor of infancy and early childhood that grows from immature liver precursor cells rather than from mature liver tissue. It is rare in absolute terms yet is the commonest liver cancer in children, and most cases appear before school age. It usually presents as a painless swelling in the upper abdomen, noticed by a parent or found on examination.
How does it differ from liver cancer in adults?
| Feature | Hepatoblastoma | Adult liver cancer |
|---|---|---|
| Typical age | Infants and toddlers | Adults and older children |
| State of the surrounding liver | Usually healthy | Usually scarred by long-term damage |
| Cell of origin | Immature precursor cells | Mature liver cells |
| Response to drug treatment | Generally good | Generally poor |
Those differences are the reason the two are handled as separate diseases despite starting in the same organ. Describing this tumor merely as a liver tumor of children, as thin sources do, leaves out that it is malignant and that it behaves quite unlike the adult disease.
What is it linked to?
Several associations are recognized, although most affected children have none of them. Being born very early or very small raises the risk, and the link grows stronger the lower the birth weight. Overgrowth syndromes, in which one side of the body or one organ develops larger than the other, are associated with it. So is an inherited bowel polyp condition caused by a fault in a gene that normally restrains a growth signaling pathway, and families carrying it are sometimes offered surveillance in early childhood. The same pathway is disturbed in a large share of tumors occurring in children with no inherited condition at all, which links the two situations.
How is it monitored?
Largely through a blood protein. Alpha-fetoprotein is made by the fetal liver and by most of these tumors, so the level falls as treatment shrinks the tumor and rises again if it returns. The catch is that the protein is naturally high in newborns and declines over the first months, so a single reading in a baby has to be read against age. Treatment combines drug therapy with surgery to remove the affected portion of the liver, which regrows; where too much of the organ is involved, transplant is an option. Outcomes are markedly better than for liver cancer in adults. The tumor belongs to the group of embryonal cancers of childhood that arise from tissue which never finished maturing, alongside Wilms tumor of the kidney.
Used in a sentence
Hepatoblastoma was confirmed on biopsy of the mass in the right lobe.
Good to know
Alpha-fetoprotein tracks the tumor, but the same protein is naturally high in newborns and falls across the first months of life, so a single raised value in a young infant is read against age rather than taken as evidence of cancer.
Word origin
Where “hepatoblastoma” comes from
The name joins the Greek hepar, meaning liver, to blastos, a sprout or germ, which marks a tumor of immature cells, and the ending -oma, meaning a swelling or growth.