Hepatoblastoma

Classification according to ICCC : VII.a

Epidemiology

Hepatoblastoma is the most common hepatic tumour in children, accounting for more than 80% of these tumours in paediatric patients. Incidence rates are highest in the age group of 0–1 years; hepatoblastoma is rare in children aged over 5 years, and is virtually non-existent in children aged over 10 years.

Clinical symptoms

Clinical symptoms depend on:

  • size of the tumour
  • growth rate of the tumour
  • age of the child, presence and location of metastases

Clinical symptoms of hepatoblastoma:

  • extended abdomen, palpable (visible) tumour mass below the right costal margin
  • general state of health is usually good, pain is rare
  • loss of appetite, abdominal pain, anaemia are less common
  • jaundice, itching of the skin, signs of coagulopathy, and swellings are rare, liver function is usually not affected
  • symptoms from metastases (10–20%): lungs, lymph nodes, brain, bones

Aetiology

  • causative factors are not known
  • low-birth-weight infants (<850 g) are at a higher risk
  • higher risk of developing hepatoblastoma:
    • association with congenital disorders and factors (hemihypertrophy)
    • genetic syndromes: Beckwith-Wiedemann syndrome, Gardner’s syndrome
    • family history: familial adenomatous polyposis (FAP)

Diagnosis

Medical history:

  1. birth weight, presence of congenital anomalies and syndromes
  2. ruling out inborn errors of metabolism (IEMs)
  3. infections, vaccinations, travelling to high-risk regions

Laboratory examination:

  1. haematology: blood count (paraneoplastic thrombocytosis, anaemia), coagulation
  2. biochemistry: liver function tests, total protein, albumin, ammonia
  3. serological testing for hepatitis, virological testing (EBV, CMV)
  4. tumour markers – AFP, older children and adolescents also CEA, Ca19-9

Imaging examination:

  1. abdominal ultrasound
  2. CT scans of abdomen, lungs and brain
  3. abdominal MRI scan
  4. 18F-FDG PET +/-

Differential diagnosis

Differential diagnosis of hepatic tumours depends on the size and character of the tumour, as well as on the patient’s age. In the differential diagnostic procedure, the following should be ruled out:

  1. non-cancerous causes:
    • haematoma
    • abscess (bacterial, mycotic, granulomatous)
  2. benign tumours:
    • mesenchymal hamartoma
    • adenoma, haemangioma
    • focal nodular hyperplasia
    • teratoma
    • infantile haemangioendothelioma
  3. secondary tumours (metastases) in the liver:
    • neuroblastoma
    • Wilm’s tumour
    • soft tissue sarcomas
    • germ cell tumours
  4. other primary hepatic tumours:
    • haemangiosarcoma
    • undifferentiated sarcoma
    • rhabdomyosarcoma of the biliary tract

Treatment

Surgical treatment

Radical surgical removal of the tumour is crucial in hepatoblastoma treatment. Radical resection provides the only real chance of curing the patient.

Surgical treatment modalities:

  • Biopsy
  • Radical resection of the tumour
  • Liver transplantation

Factors influencing the radicality of surgical procedure:

  1. size of the primary tumour and the number of affected liver segments
  2. location in the liver – relation to large vessels (portal area and hepatic hilus)
  3. presence of extrahepatic tumour(s)

Chemotherapy

Chemotherapy significantly improved survival rates of hepatoblastoma patients, and hepatoblastoma has thus become a curable tumour. Neoadjuvant chemotherapy is administered with the aim of:

  • decreasing the volume of tumour in the liver
  • eradication of lung metastases
  • eradication of extrahepatic tumour(s)

Locoregional treatment

Locoregional treatment is employed as a palliative procedure in cases where radical surgery cannot be performed, and where liver transplantation is contraindicated. Its objective is to decrease the size of tumour, and to prolong the patient’s survival. Locoregional treatment involves the following procedures:

  • radiofrequency thermal ablation
  • chemoembolisation
  • alcohol embolisation

Prognosis

Factors influencing the prognosis:

  • size and extent of the primary tumour
  • presence of extrahepatic metastases
  • initial level of AFP and the dynamics of its decline
  • tumour response to chemotherapy
  • radicality of the surgical procedure

More than 75% of children survive 5 years after the diagnosis.