A Case for Genetic Testing in Isolated Tympanic Paragangliomas.

OBJECTIVE

The aim of this study is to describe two clinical cases, which we believe highlight the need to consider routine genetic testing of all patients with new diagnosis of a tympanic paraganglioma (PGL).

PATIENTS: Two patients seen in the ENT clinic at a tertiary center with a diagnosis of isolated tympanic PGL, without family history.

INTERVENTION: Since 2016, all patients with newly diagnosed isolated tympanic PGL (glomus tympanicum) are offered review by the clinical genetic team and genetic testing of a panel of paraganglioma/phaeochromocytoma predisposition genes. Previously only those with multiple PGL or a family history were tested.

MAIN OUTCOME MEASURES: We describe the results of genetic testing, the clinical course and discuss the ongoing implications for management.

RESULTS

Both cases were identified to have a pathogenic variant in the SDHB gene after initial surgery. The clinical course for both cases was complicated by disease recurrence, as well as metastatic and secretory disease in one case. Knowledge of genetic status has influenced ongoing management, with annual MRI surveillance for other SDH-related tumors.

CONCLUSION

These two cases reinforce the importance of offering genetic testing for all cases of isolated tympanic PGL. The discovery of a significant underlying genetic variant may affect management decisions and subsequent follow-up.