Glomus Tumors

Glomus tumors, or paragangliomas, are tumors of neuroendocrine origin that often present in the head and neck near the carotid body, jugulotympanic, and vagal paraganglia. Parasympathetic derived tumor types are often benign and noncatecholamine secreting but can exert mass effects on nearby structures that result in loss of cranial nerve function, most commonly CN VIII and CN IX. Diagnosis of paragangliomas is achieved through biochemical screens of high catecholamine levels, MRI, angiograms, and biopsy showing Zellballen nesting patterns. Historical treatment has been surgical removal but can result in cranial nerve damage and other complications. Stereotactic radiosurgery (SRS) has emerged as a new preferred method of treatment, especially for small <3 cm tumors and has shown high tumor and symptom control rates in multiple studies. Suggested dosing parameters and contouring are outlined in the following chapter along with reviews of SRS studies in the last 17 years. Follow-up of paragangliomas includes lifelong surveillance using biochemical screening or imaging tests.