Causes and Risk Factors of Pheochromocytom
Pheochromocytomas originate in chromaffin cells, found in the center of the adrenal gland. Chromaffin cells also exist in nerve cells (paraganglioma). In general, the reason these chromaffin cells begin to grow is unknown, although heredity can be a factor. Though pheochromocytoma can develop at any age, it is most common in people between the ages of 30 and 60. In addition, pheochromocytomas are associated with multiple endocrine neoplasia, type II (MEN II), which is a pheochromocytoma and medullary thyroid cancer. MEN II has two subtypes: MEN IIA, which is a medullary thyroid cancer and hyperparathyroidism; and MEN IIB, consisting of pheochromocytoma, medullary thyroid cancer, and tumors of the nerves in the lips, mouth, eyes, and/or digestive tract. Pheochromocytomas are also linked to von Hippel-Lindau disease, a rare multi-system disorder, and neurofibromatosis 1 (NF1), a syndrome that causes multiple tumors, pigmented skin spots, tumors in the optic nerve, and bone lesions.
Symptoms of Pheochromocytoma
Pheochromocytomas often cause an overproduction of adrenaline (epinephrine), which results in high blood pressure. Symptoms of pheochromocytoma also include:
- Heart palpitations
- Lower chest or upper abdominal pain
- Severe headaches
- Weight loss
Pheochromocytomas can be triggered by drugs or stimulants that increase blood pressure. These can include monoamine oxidase inhibitors (MAOIs) for depression, such as phenelzine (Nardil), tranylcypromine (Parnate) or isocarboxazid (Marplan). The amino acid tyramine, another blood-pressure regulator, also can be a trigger. Tyramine is found in beer, wine, processed meats and cheese.