HEPATOCELLULAR-CARCINOMA IN CHILDREN ASSOCIATED WITH GARDNER-SYNDROMEOR FAMILIAL ADENOMATOUS POLYPOSIS

Purpose: 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 associat ed with Gardner syndrome include carcinoma of the ampulla of Vater, pa pillary carcinoma of the thyroid, and, in children, hepatoblastoma. Th e childhood malignancies often precede the appearance of other manifes tations by several years. Patients and Methods: Two patients are descr ibed. Gardner syndrome was diagnosed in a 15-year-old girl with fibrol amellar hepatocellular carcinoma after desmoid tumors and colonic poly posis developed. Classic hepatocellular carcinoma was also diagnosed i n a 9 1/2-year-old boy with familial adenomatous polyposis. Results: I n patient 1, the diagnosis of fibrolamellar hepatocellular carcinoma p receded the diagnosis of Gardner syndrome by almost 2 years. The diagn osis was confirmed by identifying a germline mutation of the adenomato us polyposis coli (APC) gene. This is the first patient reported with fibrolamellar hepatocellular carcinoma associated with Gardner syndrom e. Patient 2 had a strong family history of familial adenomatous polyp osis 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 fami lial adenomatous polyposis are reviewed. Conclusions: Because hepatoce llular carcinoma is uncommon in the pediatric and adolescent populatio n, it is important to consider the possibility of Gardner syndrome or familial adenomatous polyposis in these patients.