HB is most common between the ages of 6 months and 3 years, while HCC occurs in older children and adolescents.
What is the origin of HB?
HB arises from pluripotent hepatic stem cells or oval cells that can differentiate into hepatocytes or biliary epithelial cells.
What conditions is HB associated with?
Beckwith-Wiedemann syndrome
Hemihypertrophy
Low birth weight
FAP
What proportion of liver tumors are malignant?
2/3
What % of patients with HB have thrombocytosis?
60%
What is the most sensitive blood test to evaluate for HB and HCC?
AFP: produced by fetal liver cells and yolk sac. In neonates, levels are normally elevated and then drop to adult levels by age 6 months.
AFP is elevated in 90% of children with HB, and 70% of those with HCC
AFP levels are not associated with the level of maturity of HB
What other conditions cause elevated AFP levels?
Liver cirrhosis
Hepatitis
Germ cell tumors
Hemangioendothelioma
Testicular tumors
Gall bladder CA
Which variant of HCC is not associated with elevated AFP levels?
Fibrolamellar HCC
What should we look for when imaging for liver tumors?
Size/location of tumor
Metastatic disease
Vascular invasion to PV, HV, and VC
What is the advantage or MRI?
MRI is accurate in determining the relationship of the tumor to vascular and biliary structures.
Tumors appear homogenous and hypointense on T1 sequences, and hyperintense on T2 sequences.
Is FNA biopsy an option with liver tumors.
Yes, FNA may be sufficient to confirm the diagnosis.
What are the benign liver tumors?
Benign vascular tumors
Mesenchymal hamartoma
Adenomas
FNH
What is the role of HB histology in prognosis?
The histology of HB has minimal impact on prognosis.
What is the histologic classification of HB?
Epithelial vs. mixed (epithelial + others)
Epithelial divided into: Fetal, embryonal, macrotunular, and small cell undifferentiated.
What from of HCC has a better outcome than the typical variants?
Fibrolamellar variant
What is the COG staging system based on?
Post resection extent of disease.
Stage !: completely resected. Purely fetal histology (PFH) with minimal mitotic figures is unique group
Stage 2: microscopic residual disaese
Stage 3: gross residual disease
Stage 4: metastatic disease
What is unique about the PFH group?
When completely resected, patients with PFH and low mitotic figures (<2/10 mitotic figures) have excellent outcomes and do not require adjuvant chemotherapy. This situation occurs in 5% of patients with HB. What are factors that can compromise surgical resection?
Multifocality, bilobar involvement, portal vein or vena cava thrombosis, para-aortic lymphadenopathy, extension into liver hilum, and metastatic disease.
Why should a smaller incision be used initially?
A smaller incision should be used first to assess resectability before committing to a larger incision.
How should microscopically positive margins be managed?
Re-excision if possible.
Why should intraoperative U/S be used?
Intraoperative U/S should be used to better assess vascular involvement.
The most common cause of complications such as positive resection margins, severe intraoperative hemorrhage, and post operative liver failure secondary to Budd Chiari syndrome is unrecognized involvement of the remaining solitary hepatic vein.
What are options for anatomic resection?
R or L hepatic lobectomy
Extended R or L hepatic lobectomy
Central resection
Segmental based anatomic resection (rare)
What are the basic steps for resection?
Check for metastatic disease
Mobilize liver
Dissect poratal structures
Ligates structures supplying intended segment of liver to create line of demarcation
Dissect VC off the liver towards the VC, leaving hepatic veins as only attachment
Ligate hepatic veins within parenchyma of liver vs. extra-hepatic segments.
Perform parenchymal dissection
What is the max time allowed for clamping of portal structures?
60 minutes total, 15 minutes at a time.
What is the name of the imaginary line between GB and IVC?
Median portal fissure.
How much of the liver is removed with a L lobectomy vs a R lobectomy?
A L lobectomy removes 35% of liver parenchyma while a R lobectomy removes 65%.
What are potential postoperative complications?
Bleeding, subphrenic abscess, biliary fistula, wound infection, and biliary obstruction.
Perioperative mortality is 5%.
Why are neonates more susceptible to complications of liver resection and how is that counteracted?
Neonates have immature livers and are susceptible to postoperative hypoalbuminemia, hypoglycemia, and hypothrombinemia.
Perioperative administration of vitamin K, albumin, and vitamin K can counteract these deficiencies.
what % of HB will require liver transplant?
6%
What is the contra-indication to liver transplant in HB?
Extrahepatic disease
What are 10-year survival rates after primary transplant vs. rescue transplant (after attempted resection)?
Primary transplant has 85% 10-year survival, vs. 30-50% with rescue transplant.
When is transplant indicated for HCC?
Single lesion <5cm or up to three nodules < 3 cm. What are the disadvantages of neo-adjuvant chemotherapy?
Non-responders may experience disease progression.
What are agents used for initial therapy vs therapy for non-responders/recurrent disease?
Baseline therapy is with Cisplatin/Vincristine/5-FU or Cisplatin/Doxorubicin.
Resistant or recurrent disease is treated with etoposide/carboplatin or irinotecan
How often are unresectable tumors rendered resectable by neo-adjuvant therapy?
up to 70% of stage 3 tumors become resectable with neo-adjuvant therapy.
Only 30% of HCC are rendered resectable with neo-adjuvant therapy.
What is the role of radiation in liver tumors?
Radiation has a limited role. Not very effective.
What is suicide gene therapy?
Therapy that selectively targets tumor cells, where a non-toxic, cell permeable pro-drug, is converted to a toxic drug inside tumor cells only.
What are available options for ablative therapy?
Patients who are not candidates for transplant or resection can undergo ablative therapy.
Options incllude:
1. Chemo-embolization
2. RFA: Needle electrode delivers heat through an alternating current
3. Percutaneous injection of alcohol
4. Cryoablation: direct freezing then thawing results in cell death.
What are U/S findings that help guide ablative therapy?
RFA: echogenic micro-bubbles delineate the zone of therapy
Cryoablation: echogenic expanding rim
What is 5 year survival of HB vs HCC?
75% for HB vs 30% for HCC
What is 5 year survival with successful resection?
up to 100% for HB vs 54% for HCC
What is the primary predictor of poor prognosis?
Metastatic disease
What is the role of lung metastectomy?
Only lung lesions that do not respond to neoadjuvant chemotherapy should be resected
Reference:
1. Grosfeld's Pediatirc Surgery. Sixth edition. Chapter 30. Liver Tumors
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