Precocious puberty in a seven-year-old boy due to human chorionic gonadotropin producing pineal tumor detected by nuclear magnetic resonance computed tomographic scanning.

We report a 7-year-old boy who developed incomplete sexual precocity due to a human chorionic gonadotropin (HCG)-producing tumor in the pineal region. The patient presented enlarged testes (3 x 2 x 2 cm) bilaterally, enlarged penis, pubic hair development of Tanner Stage III, advanced bone age and growth spurt. Initial hormonal studies showed an adult male level of testosterone (13 ng/ml) and a high level of HCG as well as HCG-beta subunit. A high basal level of LH, probably due to immuno-cross-reactivity with HCG, and low basal level of FSH, probably suppressed by testosterone, did not respond to LH-RH infusion. Search for the site of HCG production failed at the initial workup, but calcification without definite signs of tumor in the pineal region was found by conventional brain CT scan. Because of subsequent progression of clinical and laboratory findings of sexual precocity, nuclear magnetic resonance computed tomographic (NMR-CT) scan was performed, which confirmed the presence of a pineal tumor three months later. The patient was treated with 4,500 rad. of radiation therapy, and responded dramatically to this regimen. He has been followed for more than two years without any signs of recurrence. We have reported here a very rare case of incomplete sexual precocity due to an HCG-producing intracranial tumor in the pineal region. An NMR-CT scan is a very useful tool for the diagnosis of some types of pineal tumor, such as germinoma, which are highly radiosensitive.