Rates of Hereditary Paraganglioma Syndromes and Secretory Head and Neck Paragangliomas: A Single Institution Experience

Introduction: Head and neck (HN) paragangliomas are benign, often nonfunctional neuroendocrine neoplasms. We aimed to characterize the rate of secretory tumors and the rate and types of genetic mutations identified in patients diagnosed with HN paragangliomas.

Methods: All patients diagnosed with HN paragangliomas and treated with stereotactic radiation (25 Gy in 5 fractions every other day) from 2009 to 2020 at a single institution were identified. A retrospective chart review was performed to record relevant laboratory results, including 24-hour urine metanephrine and catecholamine levels. Genetic testing was obtained via the Ambry Genetics Hereditary Paraganglioma and Pheochromocytoma panel.

Results: In total, 74 patients with 83 HN paragangliomas were identified. Of the 74 patients, 46 (62.2%) and 38 (51.4%) underwent laboratory and genetics testing, respectively. Just 9 (19.6%) had abnormally elevated 24-hour urine metanephrine or catecholamine results. Pathogenic/likely pathogenic mutations were found in 15 (39.5%) of patients. Among those with genetic mutations, 4/12 (33.3%) had evidence of secretory tumors, compared to 1/17 (5.9%) of those without a mutation. Conversely, 80% (4/5) patients with abnormally elevated metanephrine or catecholamine studies had a pathogenic genetic mutation, compared to 33.3% (8/24) with normal lab results.

Conclusions: This is a single institution cohort with HN paragangliomas who underwent genetic testing and urine catecholamine and metanephrine studies. We demonstrate that a large fraction of patients presenting with HN paragangliomas have pathogenic genetic mutations and elevated urinary catecholamines and metanephrines on initial evaluation. We also found that the majority of patients presenting with secretory tumors have a pathogenic genetic mutation, compared to those who did not have abnormal laboratory testing. Genetic testing and counseling, as well as laboratory studies, should thus be performed in patients diagnosed with HN paragangliomas.