Do folliculo-stellate adenomas of the pituitary gland exist or are they intrasellar meningiomas?

A tumor arising in the pituitary fossa and having some of the histological and ultrastructural features of a recently described tumor, purportedly originating from the folliculo-stellate cells of the anterior pituitary, is presented. The results of our ultrastructural and immunohistochemical studies, however, favored a meningeal origin and suggested that the neoplasm was most likely a secretory meningioma.