Why Is Biopsy Dangerous for Suspected Pheochromocytoma?
At a Glance
A biopsy of a suspected pheochromocytoma is strictly avoided because a needle can trigger a life-threatening release of adrenaline, causing severe high blood pressure. Instead, doctors safely diagnose these adrenal tumors using non-invasive blood tests, urine tests, and advanced imaging.
Your doctor was right to advise against a biopsy because poking a pheochromocytoma—a rare tumor of the adrenal gland that overproduces adrenaline—is extremely dangerous. Inserting a needle into this type of tumor can trigger a massive release of these stress hormones into your bloodstream. This sudden surge causes a “catecholamine storm,” leading to a sudden, life-threatening spike in blood pressure known as a hypertensive crisis [1][2].
The Danger of a “Catecholamine Storm”
The adrenal glands sit on top of your kidneys and are responsible for producing catecholamines, which include hormones like adrenaline (epinephrine) and noradrenaline (norepinephrine). These hormones control your body’s “fight or flight” response.
When a patient has a pheochromocytoma, the tumor stores a massive amount of these hormones. The physical trauma of a needle biopsy can cause the tumor to dump its contents directly into your system all at once. This massive rush of hormones can trigger:
- Hypertensive crisis: Dangerously high blood pressure that can lead to severe complications, such as a stroke [1].
- Cardiac arrhythmias: Rapid or irregular heartbeats, including dangerously fast heart rhythms [3][4].
- Cardiomyopathy: Sudden, severe stress and damage to the heart muscle [5][6].
While these risks sound terrifying, you are safe from these outcomes precisely because your doctor is following guidelines and avoiding a biopsy. Clinical guidelines strongly warn that if there is any suspicion an adrenal mass might be a pheochromocytoma, a biopsy must be strictly avoided [1][7].
How Doctors Diagnose It Safely
Because a biopsy is too dangerous, doctors use safe, non-invasive methods to figure out exactly what the mass is. Instead of taking a piece of the tumor, they measure the chemicals the tumor leaves behind in your body and look at specialized imaging.
Biochemical Testing (Blood and Urine)
The safest and most accurate way to detect a pheochromocytoma is by looking for broken-down pieces of adrenaline in your blood or urine. These breakdown products are called metanephrines. The standard tests include:
- Plasma free metanephrines: A simple blood draw that is highly sensitive and considered the best initial screening test [8][9][10].
- Fractionated 24-hour urine metanephrines: A test where you collect all your urine for a full 24 hours to measure the total amount of metanephrines your body is excreting [8][11].
Note on preparation: Certain common medications (like some antidepressants or over-the-counter decongestants), caffeine, and specific foods can interfere with these tests and cause false alarms. Your care team will give you instructions on what to avoid before your lab work.
Advanced Imaging
If the blood or urine tests show elevated metanephrines, doctors use specialized imaging to safely locate the tumor and confirm its characteristics.
- CT or MRI scans: Pheochromocytomas often have specific appearances. For example, they may look unusually dense on a CT scan or glow brightly in a distinct pattern on an MRI [12][13].
- Functional imaging: Advanced scans like PET/CT or MIBG scintigraphy use special tracers that only stick to certain types of cells. This allows doctors to precisely locate the tumor or check if it has spread, all without needing a needle [14][15].
By combining these blood or urine tests with imaging, your care team can confidently confirm what the adrenal mass is while keeping you entirely safe.
What Happens Next?
If a pheochromocytoma is confirmed, it can usually be treated and removed. However, to ensure your safety, any surgery is only performed after you have been given specific medications (alpha- and beta-blockers) for several weeks. These medications block the effects of the adrenaline and keep your blood pressure stable during treatment [1][7][16].
Common questions in this guide
Why can't doctors biopsy a suspected pheochromocytoma?
How is an adrenal mass tested safely without a biopsy?
What should I avoid before a metanephrine blood or urine test?
What is the treatment if a pheochromocytoma is confirmed?
Questions to Ask Your Doctor
Curated prompts to bring to your next appointment.
- 1.What specific blood or 24-hour urine tests are we using to check my metanephrine levels?
- 2.Are there any foods, supplements, or current medications (like antidepressants or decongestants) I need to stop taking before my blood or urine tests?
- 3.If the tests confirm a pheochromocytoma, what specific medications will we use to safely block the adrenaline and stabilize my blood pressure before moving forward?
- 4.Based on my lab results, will you be ordering an MRI or a specialized functional scan (like a PET/CT) to evaluate the mass?
Questions For You
Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.
Related questions
References
References (16)
- 1
Undiagnosed Pheochromocytoma Presenting as a Pancreatic Tumor: A Case Report.
Legocka ME, Toutounchi S, Pogorzelski R, et al.
Open medicine (Warsaw, Poland) 2020; (15()):103-106 doi:10.1515/med-2020-0015.
PMID: 32161778 - 2
Screening for Hereditary Pheochromocytoma in a Patient with Neurofibromatosis Type 1: A Case Report.
Ferreira Barros II, Manso F, Caldas E Silva AI, Silva Lopes Pereira MR
TouchREVIEWS in endocrinology 2021; (17(1)):79-82 doi:10.17925/EE.2021.17.1.79.
PMID: 35118451 - 3
Pathophysiology and Acute Management of Tachyarrhythmias in Pheochromocytoma: JACC Review Topic of the Week.
Nazari MA, Rosenblum JS, Haigney MC, et al.
Journal of the American College of Cardiology 2020; (76(4)):451-464 doi:10.1016/j.jacc.2020.04.080.
PMID: 32703516 - 4
ST-Segment Elevation Myocardial Infarction Related to Potential Spontaneous Coronary Thrombosis in Pheochromocytoma Crisis.
Chen F, Zheng M, Li X, et al.
Frontiers in endocrinology 2020; (11()):140 doi:10.3389/fendo.2020.00140.
PMID: 32256452 - 5
Recurrent angina and cardiac ischaemia as a presentation of pheochromocytoma: a case report.
van de Bovenkamp AA, Kalkman DN, Beijk MAM, van de Veerdonk MC
European heart journal. Case reports 2024; (8(4)):ytae153 doi:10.1093/ehjcr/ytae153.
PMID: 38645675 - 6
Ventricular Tachycardia and Resembling Acute Coronary Syndrome During Pheochromocytoma Crisis: A Case Report.
Li SJ, Wang T, Wang L, et al.
Medicine 2016; (95(14)):e3297 doi:10.1097/MD.0000000000003297.
PMID: 27057898 - 7
Case of functional paraganglioma with intraoperative hypertensive crisis during robot-assisted thoracoscopic resection.
Lachmann B, Schweigert M, Almeida AB, et al.
Surgical case reports 2024; (10(1)):127 doi:10.1186/s40792-024-01930-w.
PMID: 38772971 - 8
[Comparison of the effectiveness of various methods for determining the level of metanephrines in the diagnosis of pheochromocytomas].
Shikhmagomedov SS, Rebrova DV, Krasnov LM, et al.
Problemy endokrinologii 2023; (70(2)):46-52 doi:10.14341/probl13309.
PMID: 38796760 - 9
Single-centre study of the diagnostic performance of plasma metanephrines with seated sampling for the diagnosis of phaeochromocytoma/paraganglioma.
Boot C, Toole B, Johnson SJ, et al.
Annals of clinical biochemistry 2017; (54(1)):143-148 doi:10.1177/0004563216650463.
PMID: 27170024 - 10
Accuracy of recommended sampling and assay methods for the determination of plasma-free and urinary fractionated metanephrines in the diagnosis of pheochromocytoma and paraganglioma: a systematic review.
Därr R, Kuhn M, Bode C, et al.
Endocrine 2017; (56(3)):495-503 doi:10.1007/s12020-017-1300-y.
PMID: 28405881 - 11
Biogenic amine testing in the South African public health care system.
Legg-E'Silva D, Cave EM, Snyman T, et al.
Practical laboratory medicine 2025; (44()):e00457 doi:10.1016/j.plabm.2025.e00457.
PMID: 39968348 - 12
Adrenal Adenoma and Pheochromocytoma: Comparison of Multidetector CT Venous Enhancement Levels and Washout Characteristics.
Northcutt BG, Trakhtenbroit MA, Gomez EN, et al.
Journal of computer assisted tomography 2016; (40(2)):194-200 doi:10.1097/RCT.0000000000000343.
PMID: 26978001 - 13
Brain Metastasis of Pheochromocytoma: Diagnostic and Therapeutic Challenge.
Kammoun B, Belmabrouk H, Kolsi F, et al.
World neurosurgery 2019; (130()):391-399 doi:10.1016/j.wneu.2019.06.163.
PMID: 31260853 - 14
Positron Emission Tomography Imaging of Pheochromocytoma and Paraganglioma-18F-FDOPA vs Somatostatin Analogues.
Ebbehoj A, Iversen P, Kramer S, et al.
The Journal of clinical endocrinology and metabolism 2025; (110(2)):303-316 doi:10.1210/clinem/dgae764.
PMID: 39468778 - 15
Diagnostic Performance of (68)Ga-DOTATATE PET/CT, (18)F-FDG PET/CT and (131)I-MIBG Scintigraphy in Mapping Metastatic Pheochromocytoma and Paraganglioma.
Tan TH, Hussein Z, Saad FF, Shuaib IL
Nuclear medicine and molecular imaging 2015; (49(2)):143-51 doi:10.1007/s13139-015-0331-7.
PMID: 26085860 - 16
Phase II trial of pazopanib in advanced/progressive malignant pheochromocytoma and paraganglioma.
Jasim S, Suman VJ, Jimenez C, et al.
Endocrine 2017; (57(2)):220-225 doi:10.1007/s12020-017-1359-5.
PMID: 28685225
This information explains the risks of biopsy for suspected pheochromocytoma for educational purposes only. Always consult your endocrinologist or care team before undergoing diagnostic procedures for an adrenal mass.
Get notified when new evidence is published on Tumor of endocrine glands.
We monitor PubMed for new peer-reviewed studies on this topic and email a short summary when something meaningful changes.