<prompt> All of the following are true about chemodectoma except:Firm, rubbery, pulsatile mass, mobile from side to sideSchamblin classification is usedBiopsy is diagnosticLyre sign is splaying of internal external carotid aeries on angiography  <response>: Carotid body tumor AKA Chemodectoma Commonly found in people living at high altitudes - because of chronic hypoxia -carotid body hyperplasia. Firm, rubbery, pulsatile mass, mobile from side to side - arises from medial side of carotid body or carotid bifurcation Diagnosis: Angiography shows Lyre sign - splaying of internal external carotid aeries It is a vascular tumor - so, FNAC biopsy are contraindicated Schamblin classification is used for carotid body tumor 