Epithelial childhood liver tumors An overview of the new WHO classification for pediatric tumors

Pediatric liver tumors are very rare tumors and account for less than 1% of all childhood malignancies. By far the most common tumors are hepatoblastomas. This review discusses epithelial malignant childhood liver tumors, with particular attention to the morphology of the different hepatoblastoma subtypes. In addition, other malignant liver tumors such as the so-called hepatocellular tumor NOS and the second-most common childhood liver tumor, the hepatocellular carcinoma, are discussed. In addition to the typical morphological characteristics, the immunohistochemical and molecular aspects are also be presented, which can help to distinguish these entities with often overlapping morphology.