[Hypothalamic hamartoma with precocious puberty--a case report].

A case of hypothalamic hamartoma with precocious puberty is presented and the literature of reported cases is reviewed. An 8-year-old boy was admitted to our hospital because of precocious puberty and mental retardation. His genital development was Tanner's stage 4 and pubic hair was Tanner's stage 3. Bone age was 11 years. Plain CT showed an isodense mass in the suprasellar cistern which was not enhanced following contrast administration. Metrizamide CT cisternography showed a filling defect in the suprasellar cistern. Endocrinological evaluation revealed high levels of serum luteinizing hormone (LH) and testosterone with a marked response of LH to LH-RH injection. A left frontotemporal craniotomy was performed and the tumor was partially removed. The tumor was gray, firm and well-circumscribed with poor vascularity. Postoperatively, a right oculomotor palsy and transient diabetes insipidus developed. He was discharged ambulatory one month later. Serum LH and testosterone returned to normal and the response of LH to LH-RH injection became normal. Hamartoma was diagnosed on histological examination. Electron micrographic study showed numerous dense granules with approximately 0.1 mu in diameter, in which Judge proved LH-RH by immunofluorescent study in 1977. Our case supports the hypothesis that hypothalamic hamartoma may cause precocious puberty by autonomous secretion of LH-RH and we consider that neurosurgical treatment is recommended.