Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Headache, palpitations, and sweating in conjunction with either hypertension (may be paroxysmal) or orthostatic hypotension Pressor response to anesthesia induction or to antihypertensive or sympathomimetic drugs Biochemical evidence of excess catecholamines Adrenal tumor or tumor along the sympathetic chain (paraganglioma) +++ GENERAL CONSIDERATIONS ++ Pheochromocytoma is a catecholamine-producing tumor of the sympathoadrenal system that is usually sporadic in occurrence but can be part of a familial syndrome with multiple endocrine neoplasms These tumors predominantly secrete norepinephrine, but about 15% secrete mainly epinephrine Hypertension is the major manifestation of these tumors, which is sustained in the majority, but these tumors account for < 0.1% of underlying primary causes of hypertension Episodic hypertension due to catecholamine release is the classic manifestation, but this occurs in only about one-third of patients +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Episodic palpitation Headache Sweating Tremor Pallor +++ PHYSICAL EXAM FINDINGS ++ Sustained or episodic hypertension Orthostatic hypotension Hyperventilation Tachycardia Café-au-lait spots +++ DIFFERENTIAL DIAGNOSIS ++ Other causes of hypertension, headaches, palpitations, and orthostatic hypotension +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ A plasma epinephrine and norepinephrine > 2000 pg/mL is diagnostic Twenty-four-hour urine for metanephrines and free catecholamines If plasma catecholamine 1000–2000 pg/mL, repeat 3 hours after clonidine 0.3 mg PO; a level > 500 pg/mL suggests pheochromocytoma +++ ELECTROCARDIOGRAM ++ Tachycardias, nonspecific ST-T changes, and prominent U waves are common Less common are right and left bundle branch block +++ IMAGING STUDIES ++ CT or MRI of the abdomen to localize the tumor after a positive serum catecholamine study Iodine-131 metaiodobenzylguanidine (MIBG) scan may help find tumors not seen by CT or MRI +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Suspected pheochromocytoma +++ HOSPITALIZATION CRITERIA ++ Blood pressure > 220/120 mm Hg Planned surgery +++ MEDICATIONS ++ Preoperative alpha blockers and then beta1-selective beta blockade IV fluids to reverse volume depletion Metyrosine for refractory patients who cannot undergo surgery +++ SURGERY ++ Surgical removal of the catecholamine-producing tumor(s) +++ MONITORING ++ ECG and blood pressure in hospital and during clonidine suppression test +++ DIET AND ACTIVITY ++ Low-sodium diet Restriction of vigorous exercise until tumor is removed +++ ONGOING MANAGEMENT +++ HOSPITAL DISCHARGE CRITERIA ++ After successful surgery +++ FOLLOW-UP ++ Routine postsurgical follow-up +++ COMPLICATIONS +... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.