A 52-year-old man with an asymptomatic occlusion of the left internal carotid artery developed attacks of transient cerebral ischemia concomitant with the appearance and growth of a left thyroid adenoma. The symptoms resolved completely with excision of the tumor. Because of the unique profuse vascularity of the tumor and its large feeding artery, it is concluded that the tumor functioned as an arteriovenous shunt that decreased cerebral blood flow sufficiently to induce the attacks. Although this complex set of circumstances is unlikely to occur frequently, the case illustrates the importance of excluding the presence of other lesions which may contribute to decreased cerebral blood flow in patients with transient ischemic attacks and occlusion of the carotid arteries.
Sugarbaker EV, Chretien PB. A Tumor Shunt SyndromeTransient Cerebral Ischemia Induced by a Large Thyroid Adenoma. Arch Surg. 1972;104(2):213-215. doi:10.1001/archsurg.1972.04180020093019