Patient presents with mass in paraphaygeal region pushing carotid aery backwards, the likely cause is ?

Paragangliomas are clusters of neuroendocrine cells associated with the sympathetic and parasympathetic nervous system. Paraganglioma is the tumor of neuroendocrine cells of these paraganglia that occurs at various body sites including head, neck, thorax and abdomen. Most common location of paragangliomas is adrenal medulla, where they are referred to as pheochromocytomas. Other locations are : 1) Paraveebral ganglion (organs of zuckerkandl) and rarely bladder. 2) Paraganglia related to the great vessels of head and neck, so called aoicopulmonary chain, including carotid bodies (most common); ganglion nodosum of vagus nerve; and clusters located about the oral cavity, nose nasopharynx, larynx, and orbit. Note: Paragangliomas arising from the carotid body typically pushes the great vessels of the aoicopulmonary chain, thus the most likely diagnosis in this patient is a carotid body tumor.