Pediatric liver tumors are growths in children’s livers. These uncommon tumors differ from those found in adults. They can be benign (non-cancerous) or malignant (cancerous), presenting specific diagnostic and treatment challenges.
Understanding Pediatric Liver Tumors
Pediatric liver tumors are categorized as benign or malignant. Benign tumors account for about one-third of all focal liver lesions in children, while malignant tumors make up approximately two-thirds.
Among benign tumors, infantile hemangiomas are common, particularly within the first six months of life. These vascular tumors, an overgrowth of blood vessels, often resolve on their own within the first two years, though some may require treatment. Focal nodular hyperplasia (FNH) is another benign type, accounting for around 2% of pediatric liver tumors. FNH is often discovered incidentally.
Malignant liver tumors in children are primarily hepatoblastoma (HB) and hepatocellular carcinoma (HCC). Hepatoblastoma is the most common primary malignant liver tumor in childhood, typically diagnosed before age three, with about 100 cases annually in the United States. Risk factors include very low birth weight, prematurity, and certain genetic conditions such as Beckwith-Wiedemann syndrome, familial adenomatous polyposis (FAP), and Aicardi syndrome.
Hepatocellular carcinoma (HCC) is less common in children than hepatoblastoma, though it is the most frequent liver cancer in adults. Pediatric HCC often affects older children and adolescents, sometimes without underlying liver diseases. Predisposing factors for HCC in children include chronic liver conditions, genetic disorders like tyrosinemia, and perinatally acquired hepatitis B virus infection.
Recognizing Symptoms and Diagnosis
Children with liver tumors often present with noticeable physical signs, though these can be non-specific. The most common symptoms include a lump or mass in the abdomen, often accompanied by abdominal swelling. Parents might also observe abdominal pain, unexplained weight loss, loss of appetite, nausea, or vomiting. In some cases, jaundice, a yellowing of the skin or eyes, may also appear.
When a liver tumor is suspected, medical evaluation begins with a physical examination, focusing on the abdomen. Blood tests are routinely performed, including a complete blood count and assessment of liver enzyme levels. These tests also measure alpha-fetoprotein (AFP) levels, a protein normally produced by the fetal liver. Elevated AFP levels are frequently found in children with hepatoblastoma, making it a valuable marker for diagnosis and monitoring treatment response.
Imaging techniques are used to visualize the tumor and determine its extent. An initial ultrasound with Doppler can distinguish solid masses from fluid-filled ones and assess blood vessel involvement. Computed tomography (CT) scans and magnetic resonance imaging (MRI) provide more detailed anatomical information, including tumor size, vascular relationships, and potential spread to other areas like the lungs. These scans help guide treatment decisions.
A definitive diagnosis requires a biopsy. The tissue sample is then examined by pathologists to confirm if the tumor is benign or malignant and to identify its specific type. This analysis is important for accurate diagnosis and for creating an individualized treatment plan.
Treatment Strategies
Treating pediatric liver tumors involves a multidisciplinary team approach, bringing together specialists such as pediatric oncologists, surgeons, radiologists, and pathologists. This collaborative effort ensures comprehensive care tailored to the child’s specific condition.
Surgical resection is often the primary treatment. This can involve a partial hepatectomy, where only the affected portion of the liver is removed, aiming for complete tumor removal while preserving healthy liver tissue. Complete surgical removal is considered the only curative treatment for hepatoblastoma.
Chemotherapy plays a significant role, particularly for malignant tumors like hepatoblastoma. It may be administered before surgery (neoadjuvant chemotherapy) to shrink the tumor, making it more resectable. Chemotherapy can also be used after surgery (adjuvant chemotherapy) to eliminate any remaining cancer cells and reduce the risk of recurrence. Chemotherapy for childhood liver cancer is administered intravenously, allowing the drugs to circulate throughout the body and target cancer cells.
Liver transplantation becomes an option when tumors are unresectable, meaning they cannot be completely removed through conventional surgery, or for certain types of hepatocellular carcinoma. This procedure involves replacing the diseased liver with a healthy donor liver. Patient selection for transplantation is carefully considered, with a multidisciplinary tumor board reviewing each case.
Other therapies may be considered in specific circumstances. For instance, some vascular tumors may benefit from targeted embolization, a procedure that blocks the blood supply to the tumor. In certain cases of hepatocellular carcinoma, targeted treatments like chemoembolization or radiofrequency ablation may be used to deliver therapy directly to the tumor site. Radiation therapy may also be used.
Long-Term Outlook and Follow-Up
The long-term outlook for children with liver tumors varies significantly, depending on factors such as the tumor type, its stage at diagnosis, the child’s age, and how well the tumor responds to treatment. Benign tumors have an excellent prognosis, while malignant tumors present a more complex picture. For malignant tumors like hepatoblastoma, if the tumor is confined to the liver and completely resected, the prognosis is favorable.
Despite successful treatment, there is a possibility of recurrence for malignant tumors. Recurrence can occur in the liver or spread to other parts of the body. Certain factors, such as age at diagnosis, advanced tumor stage, and metastatic disease at diagnosis, are associated with a higher risk of recurrence.
Ongoing monitoring and follow-up care are important. This involves regular imaging scans and blood tests to detect any signs of recurrence or long-term effects of treatment. These follow-up appointments allow medical teams to manage any late effects of treatment and promptly address recurrence. Families also receive support to navigate the post-treatment phase.