From the Guidelines
Paraganglia are small clusters of neuroendocrine cells derived from neural crest tissue, located near or within the autonomic nervous system, and play crucial roles in respiratory and cardiovascular regulation. These specialized cell collections are found throughout the body, particularly along blood vessels, nerves, and in various organs 1. The most well-known paraganglia are the adrenal medulla, carotid body, and aortic bodies. Functionally, paraganglia serve as chemoreceptors that monitor blood oxygen, carbon dioxide, and pH levels. Some paraganglia, particularly those associated with the sympathetic nervous system, can produce and secrete catecholamines like epinephrine and norepinephrine 1.
Key characteristics of paraganglia include:
- Derived from neural crest tissue
- Located near or within the autonomic nervous system
- Play crucial roles in respiratory and cardiovascular regulation
- Can produce and secrete catecholamines like epinephrine and norepinephrine
- Can develop tumors called paragangliomas, which may be functional or non-functional
It is essential to note that paragangliomas can cause symptoms related to excessive catecholamine production, including hypertension, headaches, sweating, and palpitations 1. When these tumors occur in the adrenal medulla, they're specifically called pheochromocytomas, while those occurring elsewhere are termed extra-adrenal paragangliomas. The most recent and highest quality study 1 highlights the importance of understanding paraganglia and their potential to develop into tumors, emphasizing the need for proper diagnosis and treatment to prevent morbidity and mortality.
From the Research
Definition of Paraganglia
- Paraganglia are neural crest-derived cells situated in the region of the autonomic nervous system ganglia 2
- They are associated with either sympathetic tissue in adrenal and extraadrenal locations or parasympathetic tissue of the head and neck paragangliomas (HNPGLs) 3
- Paragangliomas are neuroendocrine tumors derived from the extra-adrenal paraganglia of the autonomic nervous system 4
Characteristics of Paragangliomas
- Paragangliomas are rare vascular, neuroendocrine tumors of paraganglia 3
- They are usually benign and most tumors grow slowly 3
- Physiologic activity is rare in these neoplasms and they may exhibit patterns of inheritance which predispose their occurrence in families, often with multicentricity 4
- The most common paraganglioma of the head and neck is the carotid body tumor followed by the jugulo-tympanic and vagal varieties 4
Diagnosis and Management of Paragangliomas
- Diagnosis is generally made through a combination of clinical findings and radiographic studies 4
- Magnetic resonance represents the most important imaging modality for the evaluation and characterization of suspected head and neck paraganglioma 4
- The main treatment options for HNPGL are surgery and radiotherapy 2, 4, 3
- Genetic testing is now recommended for all patients with paragangliomas to provide screening and surveillance recommendations for patients and relatives 5