Diagnosis and treatment of glomus tumors of the skull base and neck

Glomus tumors (paragangliomas) are rare, usually benign, neuroendocrine tumors that arise from nonchromaffin cells and can be multifocal or familial. They grow slowly, often infiltratively and rarely form metastases. A distinction is made between carotid, jugular, tympanicum and vagal tumors. Depending on the location, clinical symptoms include neck swelling, hearing loss with pulse-synchronous ear noise or cranial nerve failures (IX-XI). Diagnosis is often delayed because of nonspecific symptoms. Diagnostically, tumor expansion and perfusion can be well visualized by color Doppler sonography. In the T2-weighted MRI, the tumor is hyperintense, after contrast agent administration a strong enhancement occurs due to the strong vascularization. In DSA (digital subtraction angiography), even small glomus tumors can be detected. Therapeutically, operative tumor resection after embolization with, e.g., polyvinyl alcohol particles or liquid embolization can be performed. If the patient is in poor general condition or if the tumor is inoperable, different treatment techniques (intensity-modulated radiotherapy, gamma or cyber-knife) may be considered as a conservative therapeutic alternative.