<unk>  <unk>  or<unk> C) is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as<unk> chromocytes. When a tumor composed of the same cells as a<unk>  develops outside the adrenal gland, it is referred to as a paraganglioma. These neuroendocrine tumors are capable of producing and releasing massive amounts of catecholamines, metanephrines, or methoxytyramine, which result in the most common symptoms, including hypertension (high blood pressure), tachycardia (fast heart rate), and diaphoresis (sweating). However, not all of these tumors will secrete catecholamines. Those that do not are referred to as biochemically silent, and are predominantly located in the head and neck. While patients with biochemically silent disease will not suffer from the typical disease manifestations described above, the tumors grow and compress the surrounding structures of the head and neck, and can result in pulsatile tinnitus (ringing of the ear), hearing loss, aural fullness, dyspnea (difficulty breathing), and hoarseness. While tumors of the head and neck are parasympathetic, their sympathetic counterparts are predominantly located in the abdomen and pelvis, particularly concentrated at the organ of Zuckerkandl.
Pheochromocytoma
Renal oncocytoma
Histiocytoma
Pineocytoma
Pituitary adenoma
Mastocytoma
Adrenocortical adenoma
Glomus tumor