Pure Intrasellar Meningioma Mimicking Pituitary Adenoma: A Novel Neuroradiologic Finding.

Pure intrasellar meningioma is an extremely rare tumor that is difficult to diagnose as it resembles a pituitary adenoma in its clinical, endocrinologic, and radiologic presentation; it can only be distinguished through histopathologic examination. All previously reported cases of this lesion were considered those of pituitary adenoma at the initial diagnosis. This poses major challenges in clinical diagnosis. We report a case of a pure intrasellar meningioma in a 27-year-old man. A boundary between the tumor and pituitary gland may be evident on magnetic resonance imaging, thus enhancing the diagnosis of pure intrasellar meningioma.