IMMUNOHISTOCHEMICAL STUDY OF ESTROGEN RECEPTOR-RELATED ANTIGEN, PROGESTERONE, AND ESTROGEN-RECEPTORS IN HUMAN INTRACRANIAL MENINGIOMAS

Background. The estrogen receptor-related antigen (ER-D5) is a serine phosphoprotein associated with the estrogen receptor that is present only in estrogen receptor-(ER) positive tissues and has no relation with progesterone receptor (PR). This study was performed to evaluate whether immunostaining of these proteins correlated with the proliferative potential of meningiomas as evaluated by clinicopathologic features. Methods. Immunohistochemical staining of ER-D5, ER, and PR were performed on paraffin embedded sections of meningiomas from 34 patients. Results. Twenty two (64.7%) of the 34 meningiomas tested were positive for ER-D5 with exclusively cytoplasmic immunostaining. All of the cases were positive for PR but not for ER. Progesterone receptors in meningiomas were cytoplasmic and/or nuclear. The correlation of ER-D5 reactivity with histologic subtypes showed positivity rates for meningotheliomatous meningiomas of 71.4%, fibroblastic 41.7%, transitional 80%, anaplastic 100% and hemangiopericytic 100%. ER-D5 positivity rates in primary and recurrent meningiomas were 59.3% and 85.7%, respectively. Normal arachnoid tissue was positive for PR but negative for ER-D5 and ER. Patient age and sex has no significant influence on the positivity rate of meningiomas. The mean number of AgNORs in ER-D5-positive and -negative meningiomas had no statistical significance. Conclusions. This study suggests that ER-D5 has some role in the growth of the meningioma and that the expression of ER-D5 in human meningioma is independent of ER as it is in breast cancer. The localization of PR in the meningioma cells indicate that at least some of these cells are functionally active.