Frontotemporal clear cell meningioma. Report of 3 cases.

Clear cell meningioma (CCM) is an uncommon meningioma. Some cases have been reported, and the localization of most of them is the spinal region. We present 3 cases of CCMs in the frontotemporal lobes. All cases were postmenopausal women with a history of arterial hypertension and uterine leiomyomatosis. The radiologic appearance in 2 cases was similar to that of dural hematomas, and in 1 case, the imaging study was consistent with the diagnosis of meningioma. On histologic examination, there were sheets of glycogenated polygonal cells with abundant clear cytoplasm and round, uniform, bland appearing nuclei. Numerous hyalinized blood vessels and collagenous stroma with fibrillary appearance were present in 2 cases. They were immunoreactive to epithelial membrane antigen, epithelial cell adhesion molecule, and progesterone receptors. However, 2 cases showed weak and focal reaction to Her-2/neu. In our knowledge, some cases of CCMs have been reported and no immunoexpression has been noted with those markers used. These cases illustrate a rare variant of meningioma in the frontotemporal lobes and their immunohistochemical profiles. Differential diagnosis is discussed.