Specific estradiol binding in schwannomas, meningiomas, and neurofibromas

The cytoplasmic fractions of schwannomas (acoustic neuromas), meningiomas, and neurofibromas were assayed for the presence of estrogen receptors. Specific estradiol binding was detected in 7 of 16 schwannomas, 7 of 10 meningiomas, and 1 of 6 neurofibromas. A nontumorous vestibular nerve was also studied and showed no estradiol binding. In the tumors, the concentration of the estradiol binding sites as estimated by saturation binding analysis covered a wide range of values (21 to 2430 fmol/g of tumor) but, overall, meningiomas contained the highest amount of estradiol binder. A Scatchard plot analysis of one of the schwannoma specimens demonstrated high affinity estradiol binding (Ka = 1.695 X 10(10) M-1). Although there were more females than males in each tumor category, the overall incidence of estradiol binding was similar in males (5 of 11, 45%) and in females (10 of 21, 48%). In 5 cases, progestin binding was also measured and was detected in two meningiomas (both from female patients); one meningioma and two neurofibromas showed no progestin binding. A discussion is presented of the possible role of estradiol in the pathogenesis or modulation of meningeal and Schwann cell tumors as well as in the genetic disorder neurofibromatosis.