(BQ) Part 2 book "Practical differential diagnosis in surgical neuropathology" presentation of content: Meningioma, meningeal sarcoma, hemangioblastoma, central nervous system primitive neuroectodermal tumors, pineal region tumors, pituitary gland lesions, pituitary gland lesions, pituitary gland lesions,. | 19 Meningioma I N 1922, HARVEY CUSHING ADOPTED the term “meningioma” to include a variety of meningeal based neoplasms which had been previously described under a variety of names including meningothelioma, endothelioma, arachnothelioma, meningocytoma, leptomeningioma, dural exothelioma, arachnoidal fibroblastoma, and fungus of the dura mater (1,2). The morphologic heterogeneity of this group of neoplasms has been recognized for a long time. Despite the wide variety of phenotypic appearances of meningioma, it is thought that this group of neoplasms is similar in that they are derived from arachnoidal cap cells which are most frequently situated within the leptomeninges and that they share certain immunohistochemical and ultrastructural features which allow their identification. However, they continue to provide a challenge from a differential diagnostic standpoint because of the wide variation in appearance. They also continue to challenge the efforts of most to reliably predict, based on histopathology, which tumors are more likely to behave in an aggressive manner. The etiology of meningioma still remains unknown in most cases. Clearly, a subset of tumors appear to arise as a result of prior radiation therapy (3,4). In cytogenetic studies, an association with neurofibromatosis type II has pointed to an abnormality of chromosome 22 as an underlying etiology in a number of these neoplasms (5,6). Alterations in other chromosomes have been described in a subset of these tumors (7,8). Meningiomas comprise anywhere from 10-20% of all adult intracranial tumors (6). The vast majority of meningiomas arise in adults; however, pediatric-aged patients may also be affected. Intracranial meningiomas clearly show a female predominance. Some studies have suggested that growth of meningiomas may be accelerated during the luteal phase of the menstrual cycle and during pregnancy (9,10). An association between meningiomas and other hormonally dependent tumors, in .
