Pheochromocytoma
PCC High-yield Verified · Sep 2026Pheochromocytoma is a rare catecholamine-secreting tumour of the chromaffin cells of the adrenal medulla (paraganglioma when the chromaffin tissue is outside the adrenal) that causes paroxysmal or sustained hypertension and is cured by surgical removal after alpha-adrenergic blockade.
The disorder behind the headache–sweating–palpitations triad, why you do not palpate the abdomen, alpha before beta, the high-salt diet before surgery, the patient lying down for 30 minutes before a metanephrine draw, and the blood pressure and glucose that fall the moment the tumour comes out.
What’s going wrong in the body
The normal physiology, where it fails, and why the body’s compensation backfires.
01 A tumour that makes stress hormones on its own schedule
"A pheochromocytoma is a rare tumor originating from chromaffin cells in the adrenal medulla," and its manifestations "result from excessive catecholamine secretion." "Tumors that arise from extra-adrenal chromaffin cells are known as paragangliomas" — "Pheochromocytomas account for 80% to 85% of these tumors, while sympathetic paragangliomas account for 15% to 20%." "The principal catecholamines are dopamine, norepinephrine, and epinephrine," made step by step from tyrosine, with the "rate-limiting conversion of tyrosine to dihydroxyphenylalanine (DOPA) by tyrosine hydroxylase" as the first step — the step metyrosine blocks.
The receptors explain the symptoms. "α-adrenoceptors located in vascular smooth muscle cells can cause hypertension through vasoconstriction when activated by norepinephrine and epinephrine"; β-1 receptors drive the heart; and "β-2 adrenoceptors are found in peripheral blood vessels and can induce vasodilation." The two main hormones behave differently: "Norepinephrine is typically released continuously, leading to persistent hypertension, while epinephrine is released in a paroxysmal manner, which can cause tachyarrhythmias." Norepinephrine "is the predominant catecholamine secreted by PCC."
Two hidden consequences matter for nursing. First, the vessels are squeezed so tightly that the blood volume is low: patients "usually have contracted intravascular volume despite being hypertensive." Second, the body adapts: "Chronically elevated levels of norepinephrine can lead to downregulation of adrenoreceptors, which may contribute to a milder clinical presentation." Both come back after surgery, when the catecholamine supply stops abruptly and the blood pressure falls.
02 Spells and crises — what sets the tumour off
"The classic triad of symptoms in patients with PCC consists of episodic headaches, diaphoresis, and tachycardia," and "episodes of hypertension are often paroxysmal." NCI lists hypertension, headache, perspiration, "Forceful palpitations.", tremor and "Facial pallor." — "These symptoms are often paroxysmal, although sustained hypertension between paroxysmal episodes occurs in 50% to 60% of patients." Not everyone is hypertensive — "10 to 20 percent of patients may present with normal blood pressure" — and "approximately half of patients with pheochromocytoma are asymptomatic" because the tumour was found on imaging or family screening. The clue in practice: "The presence of hypertension that is resistant to multiple antihypertensive therapies should raise suspicion for pheochromocytoma."
A spell can be triggered mechanically — including by the nurse. "Mechanical factors such as abdominal palpation, sexual intercourse, coughing, sneezing, defecation, pain, extreme emotions, and exposure to cold can trigger hypertensive crises in otherwise asymptomatic catecholamine-secreting tumors." NCI adds strenuous exertion, labour and delivery, anaesthesia induction, and "Surgery or other invasive procedures, including direct instrumentation of the tumor (e.g., fine-needle aspiration)." Foods and drugs can trigger it too: "Eating foods high in tyramine (e.g., red wine, chocolate, and cheese)"; and "Severe hypertension episodes may be triggered by dopamine receptor antagonists, non-selective β-blockers, tricyclic antidepressants, corticosteroids, sympathomimetics, and neuromuscular agents." "Metoclopramide is contraindicated as it can induce hypertensive crisis," and "Glucagon can release catecholamines in PCC."
The crisis is what kills. "Hypertensive crisis can lead to cardiac arrhythmias, myocardial infarction, and even death," and the complication list includes cardiogenic shock, stroke, renal failure, pulmonary edema and hypertensive encephalopathy. "Patients with long-standing PCCs can develop severe cardiomyopathy." A quiet tumour is not a safe one: "Patients with subclinical disease are also at significant cardiovascular risk, with case reports describing sudden hypertensive crises leading to sudden death."
03 Alpha before beta — and what happens when the tumour comes out
"The definitive treatment for pheochromocytoma is surgical resection, with preoperative α- and β-adrenergic blockade being crucial," and surgery "has a success rate of more than 90%." Alpha-blockade comes first and early: it "should be initiated at the time of diagnosis and maximized preoperatively to prevent potentially life-threatening cardiovascular complications," and "A preoperative treatment period of 1 to 3 weeks is usually sufficient." "All patients with functional PPGLs should undergo preoperative blockade to prevent perioperative complications."
Beta-blockade must never come first. "Beta-adrenergic blockade must never be initiated before alpha-adrenergic blockade; doing so blocks beta-adrenergic receptor-mediated vasodilation and results in unopposed alpha-adrenergic receptor-mediated vasoconstriction, which can lead to a life-threatening crisis." Beta-2 receptors "can induce vasodilation"; take them away and the alpha squeeze is unopposed. So "At least 3 to 4 days after starting α-blockade, β-blockade with propranolol, atenolol, or metoprolol should be initiated to manage tachycardia." Even labetalol, which blocks both, "is not preferred" — its "α:β receptor antagonism ratio of 1:7" is weighted toward beta. Refill the tank while you open the vessels: "During alpha-adrenergic blockade, liberal salt and fluid intake should be encouraged because volume loading reduces excessive orthostatic hypotension both preoperatively and postoperatively." Blockade is adequate when there is "resolution of spells and a target low normal blood pressure for age," reflected by "normalizing blood pressure with mild orthostasis."
Removing the tumour removes the catecholamines in minutes, and two things fall. Blood pressure: "After ligation of the tumor blood vessel, a precipitous drop in blood pressure may occur. This is usually due to the sudden drop in endogenous catecholamine levels in the setting of chronic downregulation of alpha-adrenergic receptors" — "The most common complication following tumor removal is hypotension, which may require fluid therapy and vasopressor support for several hours." And glucose: "As catecholamine inhibits insulin secretion, hence sudden decrease in catecholamine level after the resection of a tumor can result in a rebound increase in insulin secretion" — "blood sugar should be checked regularly every 4 to 6 hours." "Postoperatively, patients should remain in a monitored environment for 24 hours." Surgery also has its own crisis risk — "Peritoneal insufflation during laparoscopic resection and tumor manipulation during surgery can cause an abrupt release of catecholamine" — which is why the surgeon handles the tumour minimally.
Causes & risk factors
Modifiable factors are teaching targets — the patient can act on them.
Signs & symptoms
Each finding tied to the mechanism that produces it — and the triage it calls for.
Diagnostics
Complications
Medications for this condition
Why each class is prescribed here — every card links to its full pharmacology page.
Alpha-blockers are first-line and come first. Phenoxybenzamine "is the usual drug of choice; prazosin, terazosin, and doxazosin (selective alpha-1-antagonists) are alternative choices." Phenoxybenzamine is "an irreversible, nonspecific alpha-adrenergic blocker" with a "half-life of approximately 24 hours," and "Selective alpha-1-adrenergic blocking agents cause less reflex tachycardia." Started at diagnosis, for about 1 to 3 weeks before surgery. Expect orthostatic hypotension and reflex tachycardia, especially if volume is low; phenoxybenzamine’s listed adverse effects also include miosis, drowsiness, fatigue, inhibited ejaculation and gastrointestinal irritation. Phentolamine — "a short-acting non-selective alpha-1 and alpha-2 antagonist with a duration of action of 10 to 15 minutes" — treats acute episodes and intraoperative hypertension.
The selective alpha-1 alternatives. Phenoxybenzamine "is the usual drug of choice; prazosin, terazosin, and doxazosin (selective alpha-1-antagonists) are alternative choices." "Selective alpha-1-adrenergic blocking agents cause less reflex tachycardia."
Only after alpha-blockade — never first. "At least 3 to 4 days after starting α-blockade, β-blockade with propranolol, atenolol, or metoprolol should be initiated to manage tachycardia." Given first, a beta-blocker removes beta-2 vasodilation and leaves "unopposed alpha-adrenergic receptor-mediated vasoconstriction, which can lead to a life-threatening crisis." Labetalol is not preferred — its α:β ratio of 1:7 means it can still provoke unopposed alpha stimulation. Non-selective beta-blockers are also on the list of crisis triggers. In pregnancy beta-blockers are used only if needed (intrauterine growth restriction).
An add-on or alternative. "Calcium channel blockers, such as amlodipine and nifedipine, can serve as alternative or add-on agents to effectively control hypertension in the preoperative period," and a short-acting one such as nicardipine can control hypertension during surgery.
For hypotension after the tumour is removed — rapid volume replacement first, then intravenous vasoconstrictors "(e.g., norepinephrine or phenylephrine)," sometimes for several hours.
Intraoperative hypertension — "Short-acting vasodilators such as nitroprusside and nitroglycerin" are among the options when tumour handling releases catecholamines.
Metoclopramide is contraindicated — it "can induce hypertensive crisis." Dopamine receptor antagonists as a group are named crisis triggers, so check any antiemetic order.
A crisis trigger and a test interferer. Tricyclic antidepressants can trigger severe hypertension episodes and can falsely raise metanephrine results.
Two roles. Corticosteroids are on the list of drugs that can trigger a hypertensive crisis; and after bilateral total adrenalectomy, lifelong steroid replacement is required.
Beyond medications
- Surgery is the cure — the Endocrine Society recommends "minimally invasive adrenalectomy for most pheochromocytomas," with "minimal handling of the lesion and avoiding spillage of tumor contents."
- High-sodium diet and liberal fluids during alpha-blockade — "Preparation should include a high-sodium diet and fluid intake to prevent postoperative hypotension."
- Avoid triggers: tyramine-rich foods (red wine, chocolate, cheese), straining, and the drugs listed above — anaesthesia induction, surgery and other invasive procedures are named triggers too.
- Metyrosine — which "inhibits tyrosine hydroxylase, the rate-limiting enzyme in catecholamine synthesis" — "can be added if needed."
- Lifelong follow-up — annual biochemical testing after surgery, and genetic screening of relatives.
Nursing considerations
The RN-specific layer — each action paired with the reason it matters.
How a real nurse thinks
The clinical-judgment loop, worked for a typical presentation — reasoning, not reference.
- 1 Recognize cues
She has had alpha-blockade for only 2 days, and a beta-blocker is due now — sourced practice is to start beta-blockade "at least 3 to 4 days after starting α-blockade." A metoclopramide order is on the chart, and metoclopramide "is contraindicated as it can induce hypertensive crisis." She is orthostatic and drinking little on a regular diet. She is constipated, and defecation is a named crisis trigger. Her glucose is raised, in keeping with catecholamine excess.
- 2 Analyze cues
Two orders could precipitate a crisis. A beta-blocker before adequate alpha-blockade removes beta-2 vasodilation and leaves unopposed alpha vasoconstriction. Metoclopramide, a dopamine antagonist, can release catecholamines. Her orthostasis reflects a contracted blood volume plus early alpha-blockade — the liberal salt and fluid that should accompany blockade are missing. Straining at stool could set off a spell.
- 3 Prioritize
First, hold the metoprolol and contact the provider — alpha-blockade has not yet run 3 to 4 days. Second, question the metoclopramide order before any dose is needed. Third, address volume — ask about a high-sodium diet and more fluid — and put fall precautions in place. Constipation prevention and glucose monitoring follow.
- 4 Generate solutions
Anticipate: beta-blocker delayed until at least day 3–4 of alpha-blockade and then used for tachycardia; metoclopramide discontinued; a high-sodium diet with liberal fluids; orthostatic vital signs; a bowel regimen to prevent straining; no abdominal palpation; glucose monitoring. The goal is spells resolved and a low-normal blood pressure with only mild orthostasis before surgery.
- 5 Take action
Withhold the metoprolol and call with an SBAR: 42-year-old with a right adrenal pheochromocytoma on phenoxybenzamine for 2 days. Metoprolol is due now and metoclopramide is ordered PRN. BP 158/96 lying and 132/84 standing with light-headedness, HR 104, constipated three days. Beta-blockade should start only after 3 to 4 days of alpha-blockade, and metoclopramide is contraindicated in pheochromocytoma. Requesting the beta-blocker be deferred, the metoclopramide discontinued, a high-sodium diet with liberal fluids, and a bowel regimen. Place fall precautions, teach her to rise slowly, and remind the team not to palpate her abdomen.
- 6 Evaluate
Over the next days her spells stop, standing blood pressure is low-normal with only mild light-headedness, and the beta-blocker is started later for tachycardia. After surgery she is monitored for 24 hours; her blood pressure dips after the tumour vein is tied and responds to fluids, and her glucose is checked every 4 to 6 hours. She leaves knowing she needs annual testing for life and that her relatives should be offered genetic screening.
Scenario — you’re the nurse
Work each question before revealing the answer. Rationales explain the wrong options too.
A 42-year-old woman has a right adrenal pheochromocytoma confirmed by plasma metanephrines about three times the upper limit and a CT scan. She was admitted for blood pressure control before laparoscopic adrenalectomy. Phenoxybenzamine was started 2 days ago. She has had several spells of pounding headache, sweating and palpitations in recent months.
Q1 Select all that apply Which orders should the nurse question for this patient? Select all that apply. - A. Oral metoprolol now, on day 2 of phenoxybenzamine
- B. IV metoclopramide PRN nausea
- C. High-sodium diet
- D. Orthostatic vital signs
- E. Abdominal examination by deep palpation each morning
Reveal answer & rationale
Q2 Multiple choice Why must a beta-blocker never be started before an alpha-blocker in pheochromocytoma? - A. Beta-blockers raise catecholamine production by the tumour
- B. Blocking beta-2 vasodilation leaves alpha vasoconstriction unopposed, which can cause a hypertensive crisis
- C. Beta-blockers cause hypoglycemia
- D. Beta-blockers interfere with the metanephrine test
Reveal answer & rationale
Q3 Select all that apply Which instructions prepare the patient for a plasma metanephrine test? Select all that apply. - A. Lie down for at least 30 minutes before the blood draw
- B. Avoid caffeinated drinks and bananas beforehand as instructed
- C. Stop all blood pressure medicines the day before
- D. Avoid stress and vigorous exercise before the test
- E. Eat a high-tyramine meal the night before
Reveal answer & rationale
Q4 Select all that apply Two hours after adrenalectomy the patient’s BP is 82/48 and she is drowsy. Which findings does the nurse anticipate and check? Select all that apply. - A. Hypotension from the sudden fall in catecholamines on downregulated receptors
- B. Hypoglycemia from rebound insulin secretion
- C. Hypertensive crisis from the anaesthetic
- D. A need for fluids and possibly vasopressors
Reveal answer & rationale
Common questions
What causes pheochromocytoma?
Which findings should a nurse report immediately in pheochromocytoma?
Which medications are used to treat pheochromocytoma?
Is the "10 percent rule" still true?
Is the 24-hour urine VMA still the test for pheochromocytoma?
Why do patients eat more salt before pheochromocytoma surgery?
Sources
- Pheochromocytoma — StatPearls — StatPearls (NCBI Bookshelf)
- Perioperative Management of Pheochromocytoma — StatPearls — StatPearls (NCBI Bookshelf)
- Pheochromocytoma and Paraganglioma Treatment (PDQ®) — Health Professional Version — National Cancer Institute (NIH)
- Catecholamine Tests — MedlinePlus lab tests — National Library of Medicine (MedlinePlus)
- Pheochromocytoma and paraganglioma: an Endocrine Society clinical practice guideline (Lenders et al., J Clin Endocrinol Metab 2014) — PubMed abstract — Endocrine Society (via PubMed)
Reviewed by Hae Suk Lee, RN
Educational summary for nursing students. Scenarios are fictional teaching cases. Always verify against current guidelines and your institution's protocols before acting in practice. Not medical advice.