Nonhemorrhagic pituitary macroadenoma producing reversible internal carotid artery occlusion: case report.

Obstruction of the internal carotid artery by a pituitary tumor is a rare occurrence, particularly in the absence of pituitary apoplexy. A cas of occlusion of the right internal carotid artery caused by a nonhemorrhagic pituitary adenoma is reported. The patient presented with a 3-month history of headaches and a progressive loss of vision in his right eye, leading to sudden complete right-sided blindness on the day of admission. Except for the visual system, the patient's clinical examination revealed nothing remarkable. There was complete restoration of blood flow in the internal carotid artery after emergency transsphenoidal resection of the tumor was performed. The patient's vision also substantially improved shortly after the surgery. Neurodiagnostic correlation, using various imaging studies, is presented. This cas also demonstrates the importance of using magnetic resonance imaging with and without contrast to demonstrate complete occlusion or thrombosis in the affected vessel.