catecholaminesecreting

Catecholamine-secreting refers to cells or tumors that produce catecholamines, notably epinephrine, norepinephrine, and dopamine. The principal sources are the chromaffin cells of the adrenal medulla and, in smaller amounts, extra-adrenal chromaffin tissue in paraganglia and certain neurons of the sympathetic nervous system. These cells release catecholamines in response to stress or neural stimuli, contributing to rapid physiological adaptation.

Catecholamines mediate the fight-or-flight response, increasing heart rate and contractility, elevating blood pressure, and promoting glucose and lipid mobilization. Normal secretion is tightly regulated by neural input and feedback mechanisms. When production is excessive or unregulated, it can cause symptoms and cardiovascular complications, including sustained or episodic hypertension.

In clinical practice, catecholamine-secreting tumors are a primary concern. Pheochromocytoma (typically adrenal) and sympathetic paragangliomas (extra-adrenal) are the main functional tumors that release catecholamines; some tumors are nonfunctional. Functional tumors often present with headaches, episodic hypertension, palpitations, sweating, and anxiety, though presentations vary.

Biochemical diagnosis relies on measuring plasma free metanephrines or urinary fractionated metanephrines, which reflect catecholamine metabolism. Positive results are followed by imaging to localize the tumor (CT or MRI) and, if needed, functional studies such as MIBG scintigraphy or targeted PET scans.

Definitive management is surgical resection. Preoperative alpha-adrenergic blockade and careful perioperative hemodynamic monitoring reduce risk of hypertensive crises. Follow-up assesses for recurrence or metastasis, and genetic evaluation is recommended due to associations with hereditary syndromes such as MEN2, VHL, NF1, and SDHx mutations.