How should a 9-year-old girl with a liver mass be managed?

Management of a 9-Year-Old Girl with a Liver Mass

Immediately refer this child to a pediatric liver transplant center with expertise in hepatobiliary surgery for multidisciplinary evaluation, as the most common malignant liver tumors in this age group—hepatoblastoma and hepatocellular carcinoma—require urgent specialized assessment to optimize survival outcomes. 1, 2

Initial Diagnostic Workup

Laboratory Evaluation

• Measure serum alpha-fetoprotein (AFP) immediately, as levels typically exceed 400 ng/dL in hepatocellular carcinoma and are often >1,000 ng/dL in hepatoblastoma 1
• Obtain complete blood count, comprehensive metabolic panel, coagulation studies (PT/INR), and liver function tests 1
• Screen for underlying chronic liver disease: hepatitis B and C serologies, ceruloplasmin (Wilson's disease), alpha-1 antitrypsin level, and metabolic screening if clinically indicated 1

Imaging Studies

• Perform contrast-enhanced CT or MRI of the abdomen with multiphasic imaging to characterize the mass, assess vascular involvement, and determine extent of disease 1, 3
• Obtain chest CT to evaluate for pulmonary metastases, as this is critical for staging and treatment planning 1, 2
• Apply PRETEXT staging system at diagnosis to determine resectability and guide early transplant referral decisions 1, 2

Differential Diagnosis by Age and Presentation

Most Likely Malignant Tumors in a 9-Year-Old

• Hepatoblastoma: Most common malignant liver tumor in children, though typically presents before age 5; gold standard treatment is cisplatin-based chemotherapy followed by complete surgical resection 1, 2
• Hepatocellular carcinoma (HCC): Unlike adults, 60-70% of pediatric HCC occurs in non-cirrhotic livers and is often advanced at diagnosis 1

Benign Lesions to Consider

• Infantile hemangioendothelioma: Most common pediatric liver tumor overall, but typically presents in infancy; focal and multifocal lesions are usually asymptomatic and involute spontaneously 1
• Hepatic adenoma, focal nodular hyperplasia, and mesenchymal hamartoma are less common in this age group 3, 4

Management Algorithm Based on Tumor Type

If Hepatoblastoma is Diagnosed

Immediate Actions:

• Refer for liver transplant evaluation at diagnosis or no later than after 2 rounds of chemotherapy if the tumor is nonmetastatic but unresectable 1, 2
• Initiate cisplatin-based chemotherapy immediately per Children's Oncology Group protocol (COG-AHEP0731) 1, 2
• Administer sodium thiosulfate (16-20 g/m²) 6 hours after each cisplatin dose to prevent ototoxicity without compromising survival 5

Surgical Decision After 2-4 Chemotherapy Cycles:

• If complete resection with negative margins is achievable: Proceed with conventional hepatic resection 2
• If tumor remains unresectable but confined to liver: Proceed directly to primary liver transplantation, which achieves 82% 10-year survival versus only 30% for "rescue" transplantation after failed resection 1, 2
• If PRETEXT IV disease or complex PRETEXT III disease: Early transplant center involvement is critical, as these patients require total hepatectomy with liver transplantation 1, 2

Management of Pulmonary Metastases:

• Children with pulmonary metastases can still achieve curative outcomes if chest CT clears after chemotherapy or if residual nodules are completely resected with tumor-free margins 1, 2

If Hepatocellular Carcinoma is Diagnosed

Immediate Actions:

• Prompt referral to liver transplant center is mandatory 1
• Unlike adults, Milan criteria do not apply to pediatric HCC—transplantation should be considered in the absence of radiological extrahepatic disease or gross vascular invasion, regardless of lesion size or number 1

Absolute Contraindications to Transplant:

• Radiological evidence of extrahepatic disease 1

Relative Contraindications:

• Major venous invasion or rapid disease progression despite chemotherapy 1

Treatment Approach:

• Complete surgical resection is the only curative option, though chemotherapy may be more effective in children than adults 1
• Successful transplant outcomes have been achieved in children with large, multifocal tumors and even microscopic vascular invasion or limited local extrahepatic extension 1

Critical Pitfalls to Avoid

• Do not delay transplant referral beyond 2 chemotherapy cycles for clearly unresectable hepatoblastoma, as this reduces 10-year survival from 82% to 30% 2
• Do not attempt aggressive conventional resection with anticipated positive margins in hepatoblastoma, as this converts a primary transplant candidate (82% survival) into a rescue transplant candidate (30% survival) 2
• Do not exclude patients with pulmonary metastases from curative intent, as complete resection after chemotherapy can achieve outcomes equivalent to non-metastatic disease 2
• Do not apply adult HCC criteria (Milan criteria) to pediatric patients, as children can achieve excellent outcomes with much larger tumors due to better tumor biology and chemosensitivity 2
• Do not perform liver biopsy if imaging and AFP are diagnostic, as this risks tumor seeding and is generally unnecessary when characteristic features are present 1, 3

Multidisciplinary Team Requirements

Coordinate care involving:

• Pediatric gastroenterologist with liver disease expertise 1
• Pediatric hepatobiliary surgeon 1, 2
• Liver transplant surgeon 1, 2
• Pediatric oncologist for chemotherapy management 2, 5
• Pediatric intensive care specialist for potential acute decompensation 1