Mediastinal paragangliomas are rare tumours derived from chromaffin cells (neuroectodermal cells) associated with sympathetic ganglion of the autonomic nervous system. They can arise from two major cluster of sympathetic ganglion cells: paraaortic (aorticopulmonary) and paravetebral (aorticosympathetic) location.1,2,3
They are vascular tumours derived from chromaffin cells associated with sympathetic ganglion of the autonomic nervous system are known by different names depending on location. Tumours arise in the medulla of the adrenal gland are termed pheochromocytomas. When tumours nests are found outside the adrenal gland, they are termed paragangliomas. 1 Theortically paraganglioma can arise from any chromaffin containing ganglion tissue within the body. Common locations include abdominal paraaortic bodies, carotid body, nodose ganglion of the vagus nerve, glomus bodies in the region of the jugular foramen and cochear promontory .1 Paraganglioma can be further classified as either functioning or non-functioning. The least common group is the mediastinal paraganglioma which has been rarely reported in the literature.
Mediastinal paragangliomas are seen in as a mass in a characteristic location in the paraaortic region of the middle mediastinum or paravetebral region of the posterior mediastunum corresponding to major cluster of sympathetic ganglion cells. Uncomplicated mediastinal paragangliomas demonstrate intense contrast enhancement.1,2
Mediastinal paraganglioma demonstrates enhencement on gadolinium-enhenced T1- weighted images with conspicuity of the lesion hightlighted by flow avoid in the adjacent mediastinal vessels on spin-echo sequences.1
Differential diagnosis on CT - based on location and contrast enhencement pattern includes: 2
- 1. Sahdev A, Sohaib A, Monson JP et-al. CT and MR imaging of unusual locations of extra-adrenal paragangliomas (pheochromocytomas). Eur Radiol. 2005;15 (1): 85-92. doi:10.1007/s00330-004-2412-3 - Pubmed citation
- 2. Drucker EA, Mcloud TC, Dedrick CG et-al. Mediastinal paraganglioma: radiologic evaluation of an unusual vascular tumor. AJR Am J Roentgenol. 1987;148 (3): 521-2. AJR Am J Roentgenol (citation) - Pubmed citation
- 3. Brown ML, Zayas GE, Abel MD et-al. Mediastinal paragangliomas: the mayo clinic experience. Ann. Thorac. Surg. 2008;86 (3): 946-51. doi:10.1016/j.athoracsur.2008.04.105 - Pubmed citation