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

Objective: This study aimed to characterize the rate of secretory tumors and the rate and types of genetic variations identified in patients diagnosed with head and neck (HN) paragangliomas. Study Design: A retrospective case review. Setting: Tertiary referral center. Participants: About 74 patients with HN paragangliomas treated with gamma knife radiosurgery. Main Outcome Measures: Genetics testing via the Ambry Genetics Hereditary Paraganglioma and Pheochromocytoma Panel, and 24-hour urine metanephrine and catecholamine levels, were obtained. Pathogenic and likely pathogenic variations were tabulated. Levels of 24-hour urinary epinenephrine, norepinephrine, metanephrine, normetanephrine, and dopamine were recorded and correlated with rates of genetic variations. Results: Of 74 patients, 46 (62.2%) and 38 (51.4%) underwent laboratory and genetics testing, respectively; 29 (39.2%) completed both. Nine (19.6%) had abnormally elevated 24-hour urine metanephrine/catecholamine, of whom eight (88.9%) had elevated normetanephrine levels. Pathogenic/likely pathogenic variations were found in 15/38 (39.5%) patients. Among those with both genetics and laboratory testing, 4/12 (33.3%) with a pathogenic variation had evidence of secretory tumors, compared with 1/17 (5.9%) of those without a variation. Conversely, 80% (4/5) of patients with abnormally elevated metanephrine or catecholamine studies had a pathogenic genetic variation, compared with 33.3% (8/24) with normal laboratory results. Conclusion: 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 variations and secreting tumors. Genetic testing and counseling, and laboratory studies, should thus be performed in patients diagnosed with HN paragangliomas.