OPTION 1

 

• The World Health Organization reserves the term pheochromocytoma for tumors arising from chromaffin cells in the adrenal medulla.

• Closely related tumors in extra-adrenal sympathetic and parasympathetic paraganglia are classified as extra-adrenal paragangliomas.

• A pheochromocytoma is an intra-adrenal sympathetic paraganglioma.

• Although arbitrary, this nomenclature emphasizes important distinctive properties of intra-adrenal tumors, including an often adrenergic phenotype, relatively low rate of malignancy, and predilection to occur in particular hereditary syndromes.

• Hereditary disorders that are well known to be associated with development of pheochromocytomas/paragangliomas are MEN2A and MEN2B, von Hippel-Lindau (VHL) disease, and neurofibromatosis type 1 (NF-1) resulting, respectively, from mutations of the RET (Rearranged in Transfection) proto-oncogene and the VHL and NF-1 tumor suppressor genes von Hippel-Lindau disease is now divided into types 1 and 2, defined by the absence or presence of susceptibility to pheochromocytomas/paragangliomas.

Pheochromocytoma

5 P’s

Paroxysmal hypertension

Palpitations

Perspiration

Pain in head

Pallor

Rule of 10

10% malignant

10% bilateral/multiple

10% in children

10% familial

10% recurrence

10% extra-adrenal

10% discovered incidentally

Key concept:

 

• Pheochromocytoma (PHEO or PCC) is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as pheochromocytes.

• When a tumor composed of the same cells as a pheochromocytoma 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