Epinephrine, Urine

Laboratory assay overview

This panel may aid in evaluating catecholamine-producing pheochromocytomas and paragangliomas (PPGLs). However, measurements of plasma free or urinary fractionated metanephrines (ie, the O-methylated catecholamine metabolites) are preferred for the initial biochemical evaluation of PPGLs because of their overall high diagnostic sensitivity [1]. To adjust for the concentration differences in random urine specimens, results are expressed as catecholamine to creatinine ratios. Most PPGLs secrete catecholamines and can cause catecholamine excess, resulting in hypertension, arrhythmia, and hyperglycemia. Left untreated, PPGLs often lead to life-threatening cardiovascular complications. The estimated prevalence of PPGLs is 0.05% to 0.1% in adults with hypertension and 1.7% in children with hypertension [2]. Recognizing the possibility of a PPGL and performing appropriate biochemical testing are crucial for the diagnosis [1]. Plasma or urine catecholamine levels may be used, in addition to metanephrine levels, to provide additional information during the initial biochemical evaluation of PPGLs (eg, when detecting dopamine-secreting paragangliomas) [2]. Intermittent or insignificant secretion of catecholamines by some PPGLs may not increase catecholamine measurements. Physiological stress and certain medications (eg, acetaminophen, labetalol, and sotalol) may increase catecholamine measurements [1]. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. ⁠⁠⁠⁠⁠⁠⁠References 1. Lenders JW, et al. J Clin Endocrinol Metab. 2014;99(6):1915-1942. 2. National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology (NCCN Guidelines®). Neuroendocrine and Adrenal Tumors. V1.2022. Accessed June 28, 2022. http://www.nccn.org

Laboratory assay overview

Collection is of greatest value for evaluation of hypertension if performed during a hypertensive episode. Test is used to evaluate hypertension, especially if paroxysmal and to evaluate orthostatic hypertension. Test is also useful in the diagnosis of pheochromocytoma and in the diagnosis and follow-up of neuroblastoma and ganglioneuroblastoma, retinoblastomas, carcinoid tumors, carotid body tumors, and stress. Preoperative evaluation of neoplasia of childhood, especially when the tumor is in or about the adrenals. Evaluate multiple endocrine adenomatosis. Evaluate patient with medullary carcinoma of thyroid (for coexistent pheochromocytoma).

Laboratory assay overview

Work up neuroblastoma; diagnose pheochromocytoma. Pheochromocytomas and occasional paragangliomas may cause persistent or paroxysmal hypertension. Work up palpitation, severe headache, diaphoresis. Urine collections are preferred to blood sampling when there is suspicion for tumor (e.g., family history of MEA II) when hypertension is not paroxysmal. Evaluate for possible multiple endocrine adenomatosis type II.

Laboratory assay overview

Work up neuroblastoma; diagnose pheochromocytoma. Pheochromocytomas and occasional paragangliomas may cause persistent or paroxysmal hypertension. Work up palpitation, severe headache, diaphoresis. Evaluate for possible multiple endocrine adenomatosis type II.