Hepatoblastoma
Key points
Usually age <4y
2/3 Paediatric malignant Liver tumours
1:1,000,000
20% present with lung mets
Pathophysiology
Originates in hepatic stem cells
Increased risk in prematurity
Associated with Beckwith-Wiedemann Syndrome and Familial Adenomatous Polyposis
History and Examination
Ask about Hep B/C (may suggest hepatocellular carcinoma instead), family history of syndromes
Look for signs of hemihypertrophy/BWS
Investigations
May present on antenatal scan
Large echogenic to hypoechoic solid lesion, typically in the right lobe of the liver
Do foetal MRI
aFP - may need serial dilutions if very high. Need nomogram - 200,000 normal 1st day of life
May be low in some cases
A biopsy needle must never go through a normal sector, and ideally not a normal segment. If this is not possible, a laparoscopic biopsy must be taken
SIOPEL Pre-treatment extent of disease - PRETEXT staging
Liver divided in 4 segments based on Couinard
PRETEXT I: The tumour is confined to one section of the liver, three ADJOINING sections are free of tumour.
PRETEXT II: The tumour involves two adjacent sections of the liver, two ADJOINING sections are free of tumour.
PRETEXT III: The tumour involves three sections of the liver, with only one section being free of tumour.
PRETEXT IV: The tumour involves all four sections of the liver
Annotated with focality, extra-hepatic disease, mets, rupture, portal/IVC involvement
POSTEXT - stage after procedure
Additional important features to view on MRI Abdomen aside from tumour and PRETEXT stage
Lymphatic involvement
Venous involvement
Hilar involvement (may require transplant)
Histological Patterns
Hepatoblastoma mirrors liver development stages
Combination of patterns: foetal, embryonal, macrotrabecular, small cell undifferentiated, cholangioblastic, stromal derivatives, teratoid
20% of tumours include stromal derivatives like osteoid, chondroid, rhabdoid elements
Occasionally includes neuronal, melanocytic, squamous, and enteroendocrine elements
Two histological types impact prognosis:
Well differentiated foetal (WDF) cells resemble foetal hepatocytes with minimal mitotic activity and can be treated safely with surgery alone without chemotherapy
Small cell undifferentiated (SCU) primitive cells show neither epithelial nor stromal differentiation and have a worse prognosis
Anatomy
Liver Couinaud segments
The liver is split by the middle hepatic vein, creating a vertical plane that extends from the inferior vena cava to the fossa of the gallbladder. This division is referred to as Cantlie's line
Horizontal plane is at point of portal vein bifurcation
Segment 1 is caudate lobe
Segments 2-8 go clockwise from upper left lobe
Middle and left hepatic veins form common trunk in 85-95%
Bile ducts
Anterior + posterior right ducts - form main right duct
Left ducts from segments 2 + 3, duct from segment 4 joins to form left duct
Complications
Ototoxicity from cisplatin
Cardiotoxicity from Doxorubicin
Outcome
Based on stage, histology, metastases and aFP at diagnosis
Low aFP poor prognosis
90-100% 5y Survival low risk
20-60% 5y Survival High risk
Standard scenario
Concern is malignancy - hepatoblastoma
Ensure stabilised by oncology team
History:
Onset of symptoms
Nutrition and feeding
Family history of FAP etc
Examination:
Mass
Stigmata of hepatic failure
Signs of BWS
Investigations:
aFP + nomogram
USS
MRI abdomen -
Sector involvement + PRETEXT
Hilar involvement - may need transplant
Relationship to vessels
Lymph nodes
Extra-hepatic disease
CT chest for staging
PRETEXT 1-3 no mets = Standard risk
4 or mets = High risk
Oncology MDT
Biopsy + Hickman line
Needle should NOT go through normal sector and ideally not normal segment
Refer to Liver MDT
Management
Enrol in trial or:
SIOPEL 6 - Standard risk - 6 cycles cisplatin monotherapy with surgery after 4th (4 weeks)
SIOPEL 4 - High risk - weekly cisplatin, doxorubicin every 3 weeks, total 8 cycles - surgery after 3 dox doses (9 weeks)
POSTEXT staging after chemo
Surgery:
Mobilise liver
Sling infra and supra hepatic IVC to prevent air emboli and control bleeding
Sling portal triad
Use USS to look at tumour extent and vascular supply
Divide arteries and veins to segments, will demarcate, divide parenchyma
No need to resect gallbladder
Need full resection with clear margins
Hemihepatectomy for POSTEXT 1-3
POSTEXT 3 may need major venous resection or transplant
POSTEXT 4 - Transplant
Extended lobectomy (trisegmentectomy) - leave behind either 2+3 on left or 6+7 on right
Resect lung mets if not responded to chemo - controversial timing - some advocate for pre liver resection
Resume chemo 3 weeks after surgery to allow healing
References
CCLG: Treatment guidelines for hepatoblastoma (including recurrent disease)
February 2020 (updated in accordance with PHITT)
Meyers, Rebecka L. "Hepatoblastoma." Pediatric Surgery NaT, American Pediatric Surgical Association, 2023. Pediatric Surgery Library, www.pedsurglibrary.com/apsa/view/Pediatric-Surgery-NaT/829121/all/Hepatoblastoma.
Jones J, Campos A, Hirano Y, et al. Couinaud classification of hepatic segments. Reference article, Radiopaedia.org (Accessed on 20 Jul 2024) https://doi.org/10.53347/rID-4474