IS Case 29: Hepatoblastoma
Imaging Sciences URMC 2008
Publication Date: 2009-05-19
A 4-month-old male who was found to have an abdominal mass on a well child visit to his primary care pediatrician. He had been doing well, without fever or gastrointestinal symptoms. An ultrasound and CT were performed. Open biopsy results showed hepatoblastoma. After a regimen of chemotherapy, a left hepatic lobectomy was performed.
Hepatoblastoma is the most common primary hepatic malignancy in childhood, usually presenting before the age of 3 years, with all cases occurring under the age of 5 years. It is twice as common in males. Clinical findings usually include a palpable abdominal mass, with abdominal pain, weight loss, nausea, and vomiting occurring less frequently. Serum alfa-fetoprotein levels are elevated in over 90% of patients, and may be used to monitor for recurrence after therapy.
The incidence of hepatoblastoma is associated with Beckwith-Wiedemann syndrome, hemihypertrophy, trisomy 18, familial polyposis coli, Gardner syndrome, Wilms tumor, biliary atresia, and in siblings of those with hepatoblastoma. Histologic subtypes include epithelial and a mixed type (epithelial and mesenchymal). The main differential considerations in the age-appropriate group are hemangioendothelioma and metastatic neuroblastoma. Hemangioendotheliomas have finer calcifications. Hepatocellular carcinoma is usually seen in older children.
Ultrasound is often the first radiologic exam performed on a child with an abdominal mass. Findings include a large heterogeneously hyperechoic mass. Hepatoblastoma is more common in the right side of the liver. Hyperechoic shadowing foci within the mass are seen with calcification, and anechoic areas with hemorrhage and necrosis. Doppler can evaluate for vessel invasion.
A CT exam is performed to evaluate extent of the tumor and for metastatic disease, which most commonly involves the lungs. On non-enchanced CT, the lesions will be hypoattenuating compared to normal liver parenchyma. On enhanced CT, there is relatively lower enhancement centrally peripheral enhancement. Coarse and chunky calcifications are often present in the mixed type.
MR examination demonstrates a heterogeneous hypointense mass on T1-weighted imaging, with hyperintense foci representing hemorrhage. T2-weighted imaging demonstrates a heterogeneously hyperintense mass with fibrous septa, which are hypointense.
Photopenia is seen on Tc-sulfur colloid examination. Gallium scanning may demonstrate increased uptake within the mass. Angiography is now rarely utilized, however, would demonstrate a hypervascular mass.
- Donnelly LF. Fundamentals of Pediatric Radiology. Saunders. 2001; 125-127.
- Dachman AH, Pakter RL, Ros PR, Fishman EK, Goodman ZD, Lichtenstein JE. Hepatoblastoma: radiologic-pathologic correlation in 50 cases. Radiology. 1987 Jul;164(1):15-9. [PMID: 3035605]
- Dahnert W. Radiology Review Manual, 5th ed. Lippincott Williams & Wilkins. 2003; 713.
- Cohen MD. Imaging of Children with Cancer. Mosby. 1992; 20-38.