A patient with Horner's syndrome, as evidenced by a droopy eyelid, was referred to the vascular lab for a carotid duplex ultrasound exam to rule-out carotid dissection. Instead of a carotid abnormality, the duplex exam showed a mass at the carotid bifurcation, consistent with a carotid body tumor or soft tissue mass. The mass was confirmed by computed tomography (CT) and magnetic resonance imaging (MRI). Pathology, following surgical excision of the mass, determined that this was a nerve sheath tumor—a less common finding at the carotid bifurcation than is a carotid body tumor.
