Pediatric Liver Tumors: Updates in Classification.

Malignant primary liver tumors are rare in children. Yet a wide histologic spectrum is seen, particularly in hepatoblastoma, the most common malignant liver tumor in children. Furthermore, there can be significant morphologic overlap with hepatocellular carcinoma, the second most common pediatric liver malignancy, and tumors with hybrid features of hepatoblastoma and hepatocellular carcinoma are also reported (currently placed in the provisional category of malignant hepatocellular neoplasm, not otherwise specified). This review provides detailed morphologic descriptions and updates in the evolving clinical context of these tumors, and presents recent molecular advances that may further help in accurate classification of these tumors, which is critical in their management.