A further case of giant intrasellar carotid aneurysm mimicking a pituitary adenoma: the relevance of a multivariate approach in differential diagnosis.

We describe a 53 year old woman who progressively showed a left extrinsic oculomotor paresis, at first suggesting ocular myasthenia, which was ruled out by a negative Tensilon test. A CT scan of the brain revealed a pituitary mass consistent with an adenoma which was confirmed by endocrinological investigation and standard MRI. Carotid angiography, performed the day before the scheduled trans-sphenoidal surgery, clearly showed a giant intrasellar aneurysm of the left carotid syphon. An extra-intracranial by-pass with occlusion of the internal carotid artery was successfully executed.