[Pediatric liver tumor: What to do?].

Two-thirds of pediatric liver tumors are malignant, but pseudotumors such as abscesses or hematoma can simulate a tumor. The pediatrician is often the first to discover a hepatic mass in a child. The diagnostic gamut varies depending on the child's age. Before the age of three years, the main diagnoses are hepatoblastoma and hemangioma, while after the age of three, hepatocarcinoma, sarcoma, focal nodular hyperplasia, and adenoma are more frequent. The laboratory findings to search for are alpha-fetoprotein whatever the age (increased in hepatoblastoma and hepatocarcinoma), beta-hCG, and urinary catecholamines in infants. Liver function is usually normal. Ultrasonography is the first-line examination to request. It confirms the hepatic location of the mass, differentiates solid from cystic tumors (cystic mesenchymal hamartoma and undifferentiated sarcoma), hypervascular findings (hemangioma in the infant, focal nodular hyperplasia in the older child), portal or hepatic thrombosis suggesting a malignant tumor, and findings of portacaval fistula predisposing to focal nodular hyperplasia and adenoma. At the end of this clinical, biological, and ultrasound examination, the pediatrician will refer the patient to a specialized center for further investigation and management, which are at best performed by pediatric oncologists, surgeons, and radiologists. Diagnostic confirmation and extension work-up will require CT or MRI depending on the patient's age and clinical state and the availability of equipment.