Hepatoblastoma is the most common malignant liver tumor in early childhood. Most patients present before the age of 3 years with an enlarging asymptomatic abdominal mass. Some patients have fever, pain, anorexia, and weight loss. The 2 most important genetic conditions associated with hepatoblastoma are Beckwith-Wiedemann syndrome and familial adenomatous polyposis.
The incidence of hepatoblastoma in familial adenomatous polyposis kindreds is 200-800 times greater than in the general population. Evidence also exists of an association between hepatoblastoma and maternal exposure to metals, paints, and oil products. A significant number of patients with hepatoblastoma (10%) have a history of prematurity with prolonged hospitalization. Unlike hepatocellular carcinoma, hepatoblastoma has no association with cirrhosis.
For evaluation of the primary tumor, MRI is the preferred imaging modality. Because of the orthogonal-imaging capability of MRI, it is superior to CT in defining tumor margins and determining tumor resectability.
However, 3-dimensional CT-reconstructed images may compare favorably to MRI. Magnetic resonance angiography (MRA) can evaluate the tumor blood supply, which is valuable information for surgical planning. Postoperatively, MRI is superior to CT in detecting residual or recurrent tumor in the surgical bed. CT is the imaging modality of choice for detecting pulmonary metastases.
One limitation of MRI is that patients with hepatoblastoma typically require sedation for the procedure because they are young. The value of MRI also may be limited by breathing motion. However, diagnostic-quality, standard-sequence MRI now can be performed in breathing-sedated patients. Rapid-scanning techniques allow diagnostic-quality MRI and MRA in breathing-sedated patients and in those capable of only limited cooperation.
Conversely, helical CT imaging of both the chest and abdomen can be performed quickly, easily, and usually without sedation.
However, CT may not be as accurate as MRI in defining tumor margins, evaluating the portal vein, or in detecting residual or recurrent tumor following surgery.