Which one is Not true regarding carotid body tumour

Ans is None Carotid body tumor (also k/a) chemodectoma or potato tumor) The tumor arises from the chemoreceptor cells* on the medial side of carotid bulb Histologically it is a non-chromaffin paraganglioma* There is an association with pheochromocytoma* Although chronic hypoxemia has been invoked as a stimulus for hyperplasia of carotid body, approximately 35% of carotid body tumors are hereditary. Approximately 5 to 7% of carotid body tumors are malignant. The risk of malignancy is greatest in young patients with familial tumors. Clinical features Usually unilateral* Present most commonly in the 5th decade* and approximately 10% have family history. The pt. often presents with a long history of several years of a slowly enlarging painless lump* at the carotid bifurcation. The mass is firm, rubbery, pulsatile and is mobile from side to side but not up and down, and can sometimes be emptied by firm pressure, after which it will slowly refill in pulsatile manner. A bruit may also be present. Investigation Doppler study Carotid angiogram FNAC & biopsy are Ca Treatment Because these tumors rarely metastasize and their overall rate of growth is slow, the need for surgical removal must be considered carefully as complication of surgery are potentially serious. The operation is best avoided in elderly patients. Schwaz 8/e writes - "The treatment of choice of carotid body tumors is surgical excision. Because these tumors are highly vascularized, preoperative tumor embolization may be an advantage to minimize operative blood loss when dealing with tumors greater than 2 cm in diameter.