MD2B - Pediatric Oncology: Hepatoblastoma

Overview

Hepatoblastoma is the most common type of liver cancer in children, with approximately 100 new cases diagnosed annually in the United States. It accounts for 43% of all pediatric liver tumors. Hepatoblastoma most frequently occurs in children under the age of 3 and is more common in Caucasians than in African Americans. It also occurs slightly more often in males than in females.

Symptoms

Hepatoblastoma often presents as a large, asymptomatic abdominal mass, typically discovered during a routine physical examination or incidentally by a parent. As the disease progresses, symptoms such as osteopenia, weight loss, anorexia (loss of appetite), nausea, vomiting, fever, and abdominal pain may develop. Children with hepatoblastoma may also exhibit normochromic normocytic anemia (characterized by pale skin and lips due to a reduced number of red blood cells) or jaundice (yellowing of the eyes and skin due to elevated bilirubin levels).

Risk Factors

Hepatoblastoma occurs more frequently in patients with Beckwith-Wiedemann syndrome and familial adenomatous polyposis (FAP). Beckwith-Wiedemann syndrome is characterized by a large tongue, enlarged organs, increased body size, umbilical hernia, abdominal wall defects, and low blood sugar during infancy. FAP is an inherited disorder marked by the development of thousands of colon polyps, which, if untreated, will progress to colon cancer. Hepatoblastoma is also more common in premature infants and those born with very low birth weight.

Diagnosis

Laboratory work

• CBC (complete blood count) with differential: A blood sample is taken to assess the number and shape of various blood cells, including red blood cells, white blood cells, and platelets.
• Chemistry panel: A blood sample is analyzed to evaluate kidney and liver function and to measure levels of salt, enzymes, and other chemicals in the blood.
• Alpha-fetoprotein (AFP) levels: A blood test is performed to measure the amount of AFP, which is produced by immature liver cells. Elevated AFP levels are found in 90% of patients with hepatoblastoma.
  • AFP levels can be monitored to assess treatment response and to detect disease recurrence.

Imaging

• X-ray: A diagnostic imaging procedure that uses electromagnetic energy beams to produce images of internal structures on film.
• Ultrasound (sonography): A diagnostic imaging test that uses high-frequency sound waves to create images of blood vessels and internal structures.
• Computed Tomography (CT or CAT) Scan: A diagnostic imaging procedure that combines X-rays and computer technology to produce cross-sectional images of the body, often used to visualize soft tissues.
• Magnetic Resonance Imaging (MRI): A diagnostic imaging procedure that uses large magnets, radio frequencies, and a computer to generate detailed images of internal structures.

Biopsy

A tissue sample is taken from the primary tumor to confirm diagnosis.

Treatment

Surgery and chemotherapy are the primary treatment modalities for hepatoblastoma. Up to 85% of the liver can be safely removed during surgery, as the remaining liver is capable of regenerating within a few months. Pulmonary metastases present at diagnosis should also be surgically removed, if feasible. Multi-agent chemotherapy is typically administered both before and after surgery, as these tumors are highly responsive to chemotherapy. Liver transplantation may be considered for children with unresectable tumors.

Prognosis

Approximately 90% of children with resectable tumors are cured, while those with unresectable tumors have survival rates around 60%. Patients who present with metastatic disease at diagnosis have a long-term survival rate of about 25%.