Isolated gonadotropin deficiency secondary to glioma in septum pellucidum

A 21-year-old man, who had had normal sexuality beforehand, noticed a decrease in libido and potency, as well as loss of ejaculation. Endocrine evaluation showed normal serum levels of gonadotropins but a low testosterone level. The response to clomiphene citrate was poor while those to luteinizing hormone-releasing hormone and human chorionic gonadotropin were within normal limits. A tumor found in the septum pellucidum through brain-computerized tomography was resected. Histologically it proved to be a mixed tumor composed of astrocytoma and oligodendroglioma. Three months after the operation the patient had recovered normal sexual functions and endocrine evaluations, including the responsiveness to clomiphene citrate, had been restored. This case suggests the existence of some stimulatory fiber for the secretion of luteinizing hormone in the septum pellucidum.