Sexual precocity due to intracranial human chorionic gonadotropin-secreting tumor: report of a case.

Human chorionic gonadotropin (HCG)-secreting tumors are one of the causes of isosexual precocity in boys. A seven-year-old boy had been noted to have an increased appetite, accelerated growth and the development of pubic hair in the previous three months. He had an elevated serum testosterone level (16.79 ng/mL). However, the response of luteinizing-hormone and follicle-stimulating-hormone to gonadotropin releasing hormone stimulation was suppressed. An intracranial tumor at the left thalamus was disclosed by a magnetic resonance image scan of the head, and an elevated HCG level (120 mIU/mL) was also noted. Sexual precocity due to an intracranial HCG-secreting tumor was diagnosed and a partial resection of the tumor followed by radiotherapy was carried out. His serum testosterone and HCG levels became undetectable, and the secondary sexual characteristics regressed after treatment.