Hepatoblastoma is the most common primary malignant liver tumor in children. It constitutes 80% of childhood liver tumors. Usually diagnosed between 6 months and 3 years of age, rare after 5 years. AFP is very elevated (>1000 ng/mL) and is a critical marker for diagnosis + monitoring. Calcification is common (50%). Right lobe predominance exists. Neoadjuvant chemotherapy + surgical resection is the standard approach. PRETEXT staging system is used for surgical planning.
Age Range
0-5
Peak Age
1
Gender
Male predominant
Prevalence
Rare
Hepatoblastoma is an embryonal tumor originating from embryonal liver cells. Wnt/beta-catenin signaling pathway activation plays a central role in pathogenesis — beta-catenin mutation is present in 80-90% of sporadic cases. Beckwith-Wiedemann syndrome (IGF2 overexpression), familial adenomatous polyposis (APC mutation), and very low birth weight are risk factors. Histologically, fetal, embryonal, small cell, and macrotrabecular subtypes exist — fetal type has the best, small cell type the worst prognosis. Intratumoral osteoid production causes calcification. AFP is intensely produced by hepatoblastoma cells — serum AFP >1000 ng/mL is highly specific for hepatoblastoma.
The combination of calcified large liver mass + AFP >1000 ng/mL in a child aged 6 months-3 years is diagnostic for hepatoblastoma. This combination is not seen in any other pediatric liver lesion. HCC is rare under 5 years and AFP is usually not as high as in hepatoblastoma. Mesenchymal hamartoma, hemangioendothelioma, and hepatic adenoma do not show calcification and elevated AFP. Neuroblastoma hepatic metastasis may show calcification but catecholamines are elevated instead of AFP.
Large mass of heterogeneous density on unenhanced CT. Calcification is seen in 50% of cases — may be coarse, amorphous, or osteoid-like. Necrosis and hemorrhage areas show low density. Usually well-defined.
Report Sentence
A _mm heterogeneous mass is observed in the right liver lobe containing internal calcifications and low-density necrosis areas.
Heterogeneous enhancement in arterial phase. Viable tumor tissue enhances intensely, necrotic and calcified areas do not enhance. Enhancement pattern reflects the histological heterogeneity of hepatoblastoma.
Report Sentence
The mass demonstrates heterogeneous enhancement in arterial phase, allowing differentiation of viable tumor tissue from necrotic/calcified areas.
Generally hypointense but heterogeneous signal on T1. Hemorrhage areas are T1 hyperintense (methemoglobin), calcification T1 hypointense, necrosis T1 hypointense. This heterogeneous T1 pattern shows the internal structural complexity of hepatoblastoma.
Report Sentence
Heterogeneous signal is observed in the mass on T1-weighted sequences, with hyperintense areas consistent with hemorrhage and hypointense areas with necrosis and calcification.
Heterogeneous hyperintense signal on T2-weighted images. Viable tumor tissue and necrotic areas are T2 hyperintense, fibrous septa and calcification are T2 hypointense. Fluid-fluid levels (hemorrhage) may be seen.
Report Sentence
Heterogeneous signal is observed in the mass on T2-weighted sequences, with hyperintense areas consistent with viable tumor/necrosis and hypointense areas with fibrosis/calcification.
Large mass of heterogeneous echogenicity on US. Calcifications appear as hyperechoic foci + posterior shadowing. Necrotic areas are hypoechoic/anechoic. Usually located in right lobe. US is usually the initial detection modality.
Report Sentence
A _mm heterogeneous solid mass is observed in the right liver lobe containing internal calcific foci and hypoechoic necrosis areas.
Criteria
Small, uniform cells resembling fetal hepatocytes. Low mitotic activity. Best prognosis.
Distinct Features
More homogeneous imaging findings. Less calcification. Good response to treatment. Surgery alone may be sufficient in pure fetal type.
Criteria
Less differentiated cells, high mitotic activity. More aggressive than fetal type.
Distinct Features
More heterogeneous imaging. Necrosis more common. Chemotherapy response variable.
Criteria
Both epithelial (fetal/embryonal) and mesenchymal components (osteoid, chondroid, rhabdomyoblastic). 20-30% of cases.
Distinct Features
Calcification most common in this type (osteoid production). Coarse calcifications prominent on CT. Chondroid component may create low-density areas.
Criteria
Small, round, undifferentiated cells. Worst prognosis. INI1 loss may be present.
Distinct Features
AFP may be low or normal (unlike other types). Calcification rare. Poor response to chemotherapy.
Distinguishing Feature
Pediatric HCC usually occurs in children >5 years, hepatoblastoma in <3 years. HCC may occur in cirrhosis/hepatitis B background. Calcification is very rare in HCC, 50% in hepatoblastoma. APHE + washout is typical in HCC, heterogeneous enhancement in hepatoblastoma.
Distinguishing Feature
Infantile hepatic hemangioma (hemangioendothelioma) usually presents at <6 months, is multiple, very bright on T2, shows peripheral nodular enhancement. AFP is normal. Hepatoblastoma is larger, solitary, calcified, AFP elevated.
Distinguishing Feature
Neuroblastoma hepatic metastasis is an important differential of calcified liver lesions in children. In neuroblastoma, the primary mass is retroperitoneal/adrenal, urinary catecholamines are elevated (not AFP). In hepatoblastoma, primary liver origin, AFP elevated.
Urgency
urgentManagement
surgicalBiopsy
NeededFollow-up
3-monthPRETEXT (PRE-Treatment EXTent of disease) staging system is used in hepatoblastoma treatment — the liver is divided into 4 sectors, the number of contiguous tumor-free sectors determines surgical resectability. Standard approach: neoadjuvant chemotherapy (cisplatin-based — PLADO or SIOPEL protocol) → AFP response monitoring → surgical resection. Liver transplantation may be life-saving in unresectable cases (PRETEXT IV or POST-TEXT III-IV). AFP is the most reliable marker of treatment response — if it doesn't decline, treatment is unsuccessful. 5-year survival is 80-90% in resectable, 30-50% in metastatic cases.
Neoadjuvant chemotherapy (cisplatin-based) + surgical resection is the standard treatment. PRETEXT staging system guides surgical planning. Cure rates are high (80%+) with early diagnosis. Liver transplantation may be considered for unresectable cases.