Pathology of the carotid space.

The complex anatomy of the carotid space within a small confined area is unique to the head and neck and allows for a vast array of pathology. This paper will review the anatomy of the carotid space from the skull base to the thorax, defining its borders at multiple levels, as well as its contents. The paper will also describe the myriad of mass lesions and vascular pathologies that may occur within the carotid space. The discussion will include anatomic considerations in differential diagnoses, imaging features, and lesion characteristics across multiple imaging modalities including CT, MRI, ultrasound, and conventional angiography. Entities discussed include paragangliomas, nerve sheath tumors, meningioma, fibromuscular dysplasia, carotidynia, thrombus, dissection, pseudoaneurysm, and pathology of the deep cervical chain lymph nodes. Understanding the complex and unique anatomy of the carotid space, as well as the nuances of navigating a broad differential, will empower the reader to make an accurate diagnosis.