Hepatocellular carcinoma in children associated with Gardner syndrome or familial adenomatous polyposis
Gardner syndrome, a variant of familial adenomatous polyposis, is characterized by colonic polyps that undergo malignant change and benign and malignant extracolonic lesions. Tumors frequently associated with Gardner syndrome include carcinoma of the ampulla of Vater, papillary carcinoma of the thyroid, and, in children, hepatoblastoma. The childhood malignancies often precede the appearance of other manifestations by several years. Two patients are described. Gardner syndrome was diagnosed in a 15-year-old girl with fibrolamellar hepatocellular carcinoma after desmoid tumors and colonic polyposis developed. Classic hepatocellular carcinoma was also diagnosed in a 9 1/2-year-old boy with familial adenomatous polyposis. In patient 1, the diagnosis of fibrolamellar hepatocellular carcinoma preceded the diagnosis of Gardner syndrome by almost 2 years. The diagnosis was confirmed by identifying a germline mutation of the adenomatous polyposis coli (APC) gene. This is the first patient reported with fibrolamellar hepatocellular carcinoma associated with Gardner syndrome. Patient 2 had a strong family history of familial adenomatous polyposis but no manifestations of Gardner syndrome. He was not tested for the APC mutation. The current literature and previously reported cases of hepatocellular carcinoma in patients with Gardner syndrome or familial adenomatous polyposis are reviewed. Because hepatocellular carcinoma is uncommon in the pediatric and adolescent population, it is important to consider the possibility of Gardner syndrome or familial adenomatous polyposis in these patients.