Thus these measurements give a more accurate diagnosis of pheos. A person with a normal plasma concentration of metanephrine and normetanephrine can be fairly confident of not having a pheo. Because of the high reliability of this tests, additional tests are not needed to rule out a pheo, significantly reducing costs. Use of the new test detected 97 percent of the tumors, whereas the other tests detected only 47 to 74 percent of tumors. Although particularly useful in diagnosis of tumors in VHL and MEN2, the test also shows promise for improved diagnosis of pheos in the much larger population of patients with high blood pressure where the tumor needs to be excluded.
Pheochromocytomas are usually benign.
They may occur in or near the adrenal glands, or anywhere along the sympathetic nervous system roughly from the base of the skull to the bladder. The most apparent symptom, caused by the increased secretion of epinephrine and norepinephrine, is hypertension, or high blood pressure. This hypertension may be constant or intermittent. Attacks may occur every few months or several times daily, and typically last less than five minutes. Physical and emotional stresses can initiate an attack.