High aromatase activity and overexpression of epidermal growth factor receptor in fibrolamellar hepatocellular carcinoma in a child.

An 11-year-old boy was admitted with a liver tumor and underwent right trisegmentectomy for a diagnosis of fibrolamellar hepatocellular carcinoma. He had suffered from bilateral gynecomastia for a year, which improved after complete resection of the tumor. The tumor cells had significant aromatase activity (8.03 pmol/g/h) and contained high levels of estradiol (82.1 pg/mL), which contributed to gynecomastia. Furthermore, overexpression of epidermal growth factor receptor was determined in the tumor cells, which suggests that antitumor strategies using epidermal growth factor receptor antagonists may be effective.