NOR-METANEPHRINE FREE (PLASMA) O.S.

Overview

Screening test for presumptive diagnosis of catecholamine-secreting pheochromocytomas or paragangliomas. Pheochromocytoma is a rare, though potentially lethal, tumor of chromaffin cells of the adrenal medulla that produces episodes of hypertension with palpitations, severe headaches, and sweating. Pheochromocytomas and other tumors derived from neural crest cells (eg, paragangliomas and neuroblastomas) secrete catecholamines (epinephrine, norepinephrine, and dopamine). Measurement of plasma free metanephrines appears to be the best test for excluding pheochromocytoma. The tests sensitivity approaches 100%, making it extremely unlikely that individuals with normal plasma metanephrine and normetanephrine levels suffer from pheochromocytoma or paraganglioma.