Overview
Introduction
Pheochromocytoma is a catecholamine secreting tumor arising from chromaffin cells of the adrenal medulla (90%) or extra adrenal paraganglia (10%, called paragangliomas).
NCLEX-RN
NCLEX-RN
Pheochromocytoma is a catecholamine-secreting tumor arising from chromaffin cells of the adrenal medulla (90%) or extra-adrenal paraganglia (10%, called paragangliomas). These tumors produce excessive epinephrine, norepinephrine, and sometimes dopamine, causing episodic or sustained hypertension. Catecholamine excess activates alpha-1 adrenergic receptors (vasoconstriction, increased SVR), beta-1 receptors (increased heart rate, contractility, renin release), and beta-2 receptors (bronchodilation, glycogenolysis). The paroxysmal nature results from intermittent tumor catecholamine release triggered by physical activity, positional changes, abdominal palpation, or certain medications. Rule of 10s: 10% bilateral, 10% malignant, 10% extra-adrenal, 10% familial (associated with MEN 2A/2B, von Hippel-Lindau, neurofibromatosis type 1). Hypertensive crisis can be triggered by anesthesia induction, direct tumor manipulation, or medications that release stored catecholamines.
Unlock full lesson + practice questions
9 more sections with scenarios, priorities, and review drills.
Final rapid review before practice
Next study step
Finish the lesson first, then choose a focused activity to apply what you just reviewed.
Continue studying
Sign in to save progress on this lesson.
Unlock the interactive lesson quiz with a plan that includes this NCLEX-RN pathway. You can still explore topic-filtered questions from the bank hubs below.