BACKGROUND The impact of blood sampling in sitting vs supine positions on measurements of plasma metanephrines for diagnosis of pheochromocytoma is unknown. METHODS We compared plasma concentrations of free metanephrines in samples from patients with primary hypertension obtained after supine rest with those obtained in the sitting position without preceding rest. We also assessed the effects...

BACKGROUND Pheochromocytomas and paragangliomas (PPGLs) are potentially lethal yet usually surgically curable causes of endocrine hypertension; therefore, once clinical suspicion is aroused it is imperative that clinicians choose the most appropriate laboratory tests to identify the tumors. CONTENT Compelling evidence now indicates that initial screening for PPGLs should include measurements ...

Abstract Introduction Pheochromocytomas are rare neuroendocrine catecholamine-producing tumors that arise from either the adrenal medulla (PHEO) or extra-adrenal paraganglionic tissues (paraganglioma/PGLs). PHEO is responsible for about 0.01–0.1% of cases hypertension. Assessment plasma/urinary levels metanephrines (catecholamines metabolites) now considered gold standard diagnosis PHEOs. In th...

We review our data on the measurement of catecholamines and their metabolites in 19 patients with pheochromocytoma. All the assays were specific high-performance liquid chromatographic procedures with electrochemical detection. The assay of fractionated metanephrines was 100% sensitive. Normal values for both urinary norepinephrine and epinephrine were found in two asymptomatic patients with ph...

BACKGROUND: Biochemical testing for pheochromocytoma by measurement of fractionated plasma metanephrines is limited by false positive rates of up to 18% in people without known genetic predisposition to the disease. The plasma normetanephrine fraction is responsible for most false positives and plasma normetanephrine increases with age. The objective of this study was to determine if we could i...