Meningiomas mimicking cerebral schwannoma. A brain tumor with histological features reminiscent of schwannoma with underlying meningioangiomatosis was subjected to electron microscopic and immunohistochemical analysis, which confirmed the neoplasm as a meningioma. This prompted reexamination of a similar tumor, described in a previous publication as a cerebral schwannoma, with identical immunohistochemical techniques. The results obtained favored alteration of this diagnosis to that of meningioma. This experience has led the authors to recommend the use of immunohistochemistry techniques when evaluating unusual intracranial neoplasms. 