Hepatoblastoma

Hepatoblastoma Epidemiology Hepatoblastoma occurs predominantly in children younger than 3 years old of age. The etiology is unknown. Hepatoblastomas are associated with familial adenomatous polyposis; alteration in the antigen-presenting cell (APC)/β-catenin pathway have been found in s majority of tumors evaluated. Hepatoblastoma is also associated with Beckwith-Wiedemann syndrome, which can show a similar loss of genomic imprinting of the insulin-like growth factor-2 gene. Low birth weight is associated with increased incidence of hepatoblastoma, with the risk increasing as birth weight decreases. Pathogenesis Hepatoblastoma can be epithelial type, containing fetal or embryolical malignant cells (either as a mixture or as pure elements), or the mixed type, containing mesenchymal and epithelial elements. Pure fetal histology predicts a more favorable outcome. Clinical Manifestations Hepatoblastoma generally presents as a large, asymptomatic abdominal mass. It arises from the right lobe three times more often than the left and is usually uniformical. As the disease progresses, weight loss, anorexia, vomiting, and abdominal pain may ensue. Metastatic spread of hepatoblastoma most commonly involves regional lymph nodes and the lungs. A valuable serum tumor marker, α-fetoprotein (AFP), is used in the diagnosis and monitoring of hepatic tumors. AFP level is elevated in almost all hepatoblastomas. Bilirubin and liver enzymes are usually normal. Anemia is common, and throbocytosis occurs in about a third of patients. Hepatitis B and C serology should be obtained but are usually negative in hepatoblastoma. Diagnostic imaging should include plain radiographs and ultrasonography of the abdomen to characterize the hepatic mass. Ultrasonography can differentiate malignant hepatic masses from benign vascular lesions. Either CT or MRI is an accurate method of defining the extent of intrahepatic tumor involvement and the potential for surgical resection. Evaluation for metastatic disease should include CT of the chest and bone scan. Treatment In general, the cure of malignant hepatic tumors in children depends on complete resection of the primary tumor. As much as 85% of the liver can be resected, with hepatic regeneration noted within 3-4 months after surgery. Cisplatin in combination with vincristine and 5-fluorouracil or doxorubicin is effective treatment for hepatoblastoma and increase the chances of cure after complete surgical resection. In low-stage tumors, survival rates more than 90% can be achieved with multimodal treatment, including surgery and adjuvant chemotherapy. With tumors unresectable at diagnosis, survival rates approximately 60% can be obtained. Metastatic disease further reduces survival, but complete regression of disease can often be obtained with chemotherapy and surgical resection of the primary tumor and isolated pulmonary metastatic disease resulting in survival rates about 25%.