Category: Adrenal Disorders
To report a rare case of bilateral head and neck paragangliomas (PGLs) in conjunction with a succinate dehydrogenase complex subunit D (SDHD) gene mutation. We highlight the importance of keeping paragangliomas in the differential diagnoses of an individual with hypertension. This case also emphasizes the importance of familial screening of all first-degree family relatives of patients who test positive for germline mutations.
Methods : We report the case of a 43-year-old man who presented to our institution with uncontrolled hypertension and recurrent episodes of headaches and syncope. His admitting blood pressure was 174/103 mmHg. He had some bilateral neck swelling. Biochemical evaluation resulted in elevated urine and plasma metanephrines. A CT soft tissue neck revealed a 0.8 cm right carotid body tumor, a 1.7 cm left carotid body tumor, and a 1.2 cm right glomus vagale tumor. Initially, the right carotid body tumor was embolized by Neurosurgery. Otolaryngology then did a right neck dissection to remove the right carotid body and glomus vagale tumors.
Results : Pathologic evaluation of the tumors confirmed that they were histologically and immunohistochemically consistent with PGLs and negative for malignancy. Genetic testing revealed that he was heterozygous for the presence of an SDHD c.13_14delTG pathogenic mutation, consistent with the diagnosis of Hereditary PGL-Pheochromocytoma Syndrome type 1.
Discussion : PGLs are rare, typically benign tumors that originate from neuroendocrine tissue. They have an incidence of 1 in 300,000 per year. Up to 35% of these tumors can be hereditary and the majority are associated with germline mutations in genes encoding subunits of the succinate dehydrogenase enzyme complex. The carotid body is the most common location and are frequently multifocal in origin. While there are no specific guidelines for treatment of bilateral head and neck PGLs, therapeutic options include surgical resection, radiation therapy, stereotactic radiosurgery, embolization, or a combination of these modalities.
Conclusion : The patient we described in this case developed worsening postural dizziness and headaches over the course of 20 years. Multiple resources were utilized before arriving at the diagnosis of bilateral carotid body PGLs. Prior literature states that PGLs of the head and neck do not typically produce catecholamines and are therefore diagnosed late when a mass effect syndrome occurs on nearby organs. While the majority of head and neck PGLs are non-secreting, our case emphasizes the possibility that secretory ones may be more common than previously thought. Further research is needed to gain a better understanding of bilateral head and neck PGLs.
I am a 3rd year resident physician at Dell Seton Medical Center at UT in Austin. I will be the Chief Resident in Quality and Safety next year and will be applying for an Endocrinology fellowship!
Dell Seton Medical Center at University of Texas at Austin
Endocrinologist at Dell Seton Medical Center at the University of Texas at Austin