Hepatoblastoma Arising in a Pigmented β-catenin-activated Hepatocellular Adenoma: Case Report and Review of the Literature.

Hepatoblastoma is the most common malignant liver tumor in childhood. It has been associated with a variety of constitutional syndromes and gene mutations. However, there are very few reports of associations with pediatric hepatocellular adenomas (HCAs) and no reported associations with pigmented HCAs (P-HCAs). We present a unique case of hepatoblastoma arising in a background of 2 β-catenin-activated HCAs, one of which is pigmented, in a 4-year-old child. The gross, histologic, and immunohistochemical features are described for each tumor. In addition, the literature is reviewed with specific emphasis on the clinical and pathologic features of B-HCAs. Although the potential of β-catenin-activated HCAs to progress to hepatocellular carcinoma has been well documented, there are very few reports of their potential to progress to hepatoblastoma. We not only present such a case, but, to our knowledge, we also present the first case of a P-HCA in a child.