Clinical Guides
Pheochromocytoma
A clinically focused, India-adapted guide to pheochromocytoma and paraganglioma recognition, biochemical confirmation, genetic and anatomical assessment, crisis care, alpha-first preparation, surgery and lifelong risk-based surveillance.
MedNext Academy | 13 min read
Pheochromocytoma
A clinically focused, India-adapted guide to pheochromocytoma and paraganglioma recognition, biochemical confirmation, genetic and anatomical assessment, crisis care, alpha-first preparation, surgery and lifelong risk-based surveillance.
Summary
Pheochromocytoma is a catecholamine-producing neuroendocrine tumour arising from adrenal chromaffin tissue; the related term paraganglioma describes extra-adrenal tumours from sympathetic or parasympathetic paraganglia. Together they are called PPGL. Presentation ranges from an incidental adrenal mass or inherited-syndrome screen to episodic headache, sweating, palpitations and severe hypertension. The classic triad is memorable but insufficiently sensitive: some patients are normotensive, some secrete little catecholamine, and others present through cardiomyopathy, stroke, shock or pregnancy complications. Diagnosis should establish biochemical evidence before tumour-localising imaging except when an emergency already requires imaging. Recommended initial tests are plasma free metanephrines or urinary fractionated metanephrines collected and interpreted under controlled conditions. Positive results require appraisal of sampling posture, acute illness, medicines and degree of elevation rather than a binary label. A functional tumour must be prepared before elective resection. Alpha-adrenergic blockade comes before any beta-blocker; isolated beta-blockade can leave unopposed alpha vasoconstriction and trigger dangerous hypertension. Volume expansion, anaesthetic planning and experienced adrenal surgery are integral treatment, not optional details. Every patient merits discussion of germline testing because hereditary disease is common enough to alter surgery, family care and surveillance. Metastatic potential cannot be excluded by bland histology alone. This guide is an educational, quarantined draft and does not replace an endocrine, genetic, anaesthetic or surgical plan.
How Common Is It?
PPGL is uncommon, and prevalence estimates vary markedly with the population studied, test thresholds and whether silent tumours found through imaging or family screening are counted. It explains only a small minority of hypertension in unselected clinics, yet the pre-test probability rises in an adrenal mass, a known susceptibility syndrome, a previous PPGL, characteristic paroxysms, paradoxical blood-pressure responses, or unexplained catecholamine-related cardiomyopathy. Referral-centre series over-represent large, hereditary, recurrent and metastatic disease and should not be presented as community incidence. Conversely, autopsy and incidentaloma observations show that clinically unsuspected tumours occur. A simple national Indian prevalence is not established by the cited international guidance. Access to reliable metanephrine assays, cross-sectional imaging, nuclear medicine and genetic services differs between metropolitan tertiary centres and district settings, changing observed case ascertainment. PPGL may occur at any age. Younger age, multifocal or bilateral disease, head-and-neck paraganglioma, a family history, or metastatic presentation increases suspicion of a germline cause but does not make sporadic disease impossible in older adults. Pregnancy-associated PPGL is rare but carries disproportionate maternal and fetal risk when missed. Recurrence can appear many years after apparently complete resection, so a five-year disease-free interval is not synonymous with cure. Epidemiological figures should guide service awareness, not rule an individual patient in or out; symptoms, biochemical findings, tumour location, genotype and longitudinal behaviour determine that patient’s risk.
Risk Factors
A substantial minority of PPGLs are associated with inherited susceptibility. Relevant genes include RET in multiple endocrine neoplasia type 2, VHL, NF1, the SDHx family, MAX, TMEM127 and others; the gene spectrum and testing panels continue to evolve. Ask about relatives with pheochromocytoma, paraganglioma, medullary thyroid carcinoma, hyperparathyroidism, renal-cell carcinoma, retinal or central nervous system haemangioblastoma, gastrointestinal stromal tumour, pituitary tumour, unusual early stroke or unexplained sudden perioperative death. Examine for syndromic clues without allowing their absence to reassure falsely. A previous PPGL is itself a risk factor for multifocal, recurrent or metastatic disease, particularly with young onset, extra-adrenal location, large tumour or an SDHB pathogenic variant. An adrenal incidentaloma that is not unequivocally benign on imaging requires a hormone-excess assessment before biopsy or surgery. Triggering circumstances do not cause the tumour, but anaesthesia, tumour manipulation, childbirth, glucocorticoids, sympathomimetics, stimulants, monoamine-oxidase inhibition and some interacting drugs can precipitate a crisis in susceptible patients. The clinical history should therefore include prescribed, over-the-counter and recreational substances. There is no evidence that ordinary stress, spicy food or a patient’s personality creates PPGL, and dietary supplements should not be promoted as prevention. Pregnancy changes the risk-benefit balance of imaging, blockade, timing of surgery and delivery. Because genotype affects distribution and follow-up, genetic counselling should cover possible results, uncertain variants, insurance and family implications, consent, confidentiality, cost and cascade testing rather than ordering a panel without preparation.
Diagnosis
History
Ask whether spells are abrupt and episodic or sustained, recording headache, sweating, palpitations, tremor, pallor, chest or abdominal pain, dyspnoea, panic-like sensations, weight loss, heat intolerance, constipation and orthostatic symptoms. Document home and clinic blood pressure, crises during anaesthesia or procedures, adrenal imaging, pregnancy, family history and every medicine or substance. Establish acute target-organ symptoms before pursuing an outpatient work-up.
Examination
Measure blood pressure correctly, including supine and standing values when safe, heart rate, temperature, hydration, perfusion and features of heart failure or neurological injury. Look for syndromic signs and neck or abdominal masses, but do not repeatedly palpate a suspected tumour. In an unstable patient, airway, breathing, circulation, glucose, ECG and organ injury take precedence.
Investigations
Initial biochemistry uses plasma free metanephrines or urinary fractionated metanephrines. For plasma testing, quiet supine rest and position-specific reference intervals reduce false positives. Review acute illness, obstructive sleep apnoea, renal impairment, caffeine, nicotine, strenuous exercise and interfering medicines with the laboratory; never stop essential treatment unsafely. Marked, coherent elevation carries more weight than a borderline result. Repeat optimized sampling or specialist second-line evaluation may resolve ambiguity. Once biochemical evidence is clear, localise with adrenal-protocol CT; prefer MRI when radiation should be limited, including pregnancy, or for head-and-neck disease. Functional imaging is selected by genotype, tumour distribution and proposed therapy, not ordered reflexively. Evaluate glucose, electrolytes, renal function, ECG and cardiac injury, and arrange accredited germline testing with counselling.
Differential Diagnosis
Common mimics greatly outnumber PPGL. Panic disorder, menopausal vasomotor symptoms, hyperthyroidism, hypoglycaemia, arrhythmia, medication withdrawal, stimulant or cocaine exposure, obstructive sleep apnoea, labile essential hypertension, pain and autonomic seizures can produce episodic palpitations, sweating or hypertension. Acute porphyria, mast-cell activation, carcinoid syndrome and baroreflex failure are less common considerations chosen from the phenotype. A clinician should not dismiss spells as anxiety before checking objective features, yet should also not diagnose a rare tumour from nonspecific symptoms alone. Biochemical false positives can follow seated or stressful plasma collection, acute critical illness, strenuous exercise, nicotine or caffeine, sleep deprivation, renal dysfunction and analytical or pharmacological interference. Tricyclic antidepressants and serotonin-noradrenaline reuptake inhibitors may raise normetanephrine; sympathomimetics, levodopa and other agents require assay-specific review. Acetaminophen interference depends on the laboratory method. Borderline elevation should trigger controlled repeat testing and laboratory discussion rather than immediate surgery. Adrenal differentials include lipid-rich or lipid-poor adenoma, adrenocortical carcinoma, metastasis, myelolipoma, haemorrhage, cyst and primary aldosteronism or cortisol-producing lesions. Extra-adrenal masses can be sympathetic paraganglioma, nonsecretory head-and-neck paraganglioma, schwannoma, ganglioneuroma or other neuroendocrine tumour. Imaging cannot safely exclude functional PPGL before adrenal biopsy. Hypertensive emergencies caused by renal, vascular, endocrine, obstetric or toxicological disease require parallel assessment; treatment must address organ injury while specialist biochemical confirmation proceeds after stabilization.
Management
Stable confirmed functional PPGL should enter a multidisciplinary pathway involving endocrinology, endocrine surgery or urology, anaesthesia, genetics, radiology, cardiology when indicated and nuclear medicine or oncology for multifocal or metastatic disease. Definitive treatment for a resectable adrenal pheochromocytoma is usually minimally invasive adrenalectomy in an experienced centre; large, invasive or anatomically complex tumours may require an open approach to avoid rupture and obtain safe control. Extra-adrenal tumours need location-specific expertise. Selected hereditary bilateral disease may justify cortical-sparing surgery, balancing recurrent tumour against permanent adrenal insufficiency. Before elective surgery, begin alpha-adrenergic blockade, commonly phenoxybenzamine or a selective alpha-1 blocker according to specialist protocol, and titrate against seated and standing blood pressure and symptoms. Prepare for 7–14 days when feasible, then expand salt and fluid intake unless heart or renal failure makes that unsafe. Add a beta-blocker only after adequate alpha blockade when tachycardia persists. Correct volume, glucose and electrolytes and assess catecholamine cardiomyopathy. Surgery requires invasive monitoring, short-acting vasoactive drugs, experienced anaesthesia and postoperative surveillance for hypotension, hypoglycaemia and bleeding. A crisis is an intensive emergency: stop triggers, control blood pressure with rapidly titratable intravenous vasodilator or alpha blockade under expert monitoring, treat arrhythmia and organ failure, and avoid unopposed beta-blockade. Metastatic or unresectable disease is individualized using debulking, radionuclide therapy, radiotherapy, chemotherapy, targeted systemic therapy and symptom blockade. Evidence is heterogeneous; genotype, tracer avidity, pace, burden and patient goals should guide selection.
Prescribing Information
Preoperative blockade is a supervised clinical process rather than a copyable dose schedule. Phenoxybenzamine provides nonselective, irreversible alpha blockade but may produce marked orthostasis, nasal congestion and postoperative hypotension. Selective alpha-1 blockers such as doxazosin are alternatives used by experienced teams; comparative evidence does not justify declaring one universally superior. Titrate gradually with home or observed seated and standing measurements, counsel about falls, and reassess renal and cardiac tolerance. High sodium intake and liberal fluid are intended to reverse catecholamine-related volume contraction after blockade, but can worsen heart failure, advanced kidney disease or severe oedema; individualize them. Beta-blockers control persistent tachycardia only after alpha blockade is established. Starting propranolol, metoprolol or labetalol as isolated initial treatment can permit unopposed vasoconstriction; labetalol’s beta-to-alpha effect is unsuitable as the primary blockade strategy. Calcium-channel blockers or metyrosine may be adjuncts in selected patients under specialist care. During crisis, use monitored, short-acting intravenous agents such as phentolamine, sodium nitroprusside or nicardipine according to availability and organ state, not intramuscular or slow oral improvisation. Treat ventricular dysfunction, pulmonary oedema, ischaemia and shock with critical-care support. Review tricyclics, SNRIs, stimulants, decongestants, antiemetics and perioperative drugs, but do not abruptly withdraw dependence-forming or essential medicines without a plan. Pregnancy requires maternal-fetal and endocrine pharmacology review. After resection, monitor pressure, glucose and volume closely; biochemical follow-up and long-term surveillance remain necessary even when symptoms resolve.
When to Refer
Refer promptly to endocrinology when plasma or urine metanephrines are convincingly elevated, an adrenal or paraganglial mass is hormonally suspicious, a patient has a previous PPGL or a syndrome-associated pathogenic variant, or recurrent stereotyped spells coexist with severe or labile hypertension. The referral should include exact assay, units, reference interval, sampling position and rest period, renal function, potassium, glucose, medicines, acute illness, imaging files and report, family pedigree, pregnancy status and prior tumour pathology. Borderline results are best reviewed with the biochemical laboratory before serial scans. Refer to an experienced multidisciplinary centre for every confirmed tumour before biopsy, anaesthesia or resection; specialist urgency rises with pregnancy, childhood or young adulthood, bilateral or multifocal disease, paraganglioma, suspected metastasis, severe cardiovascular disease, diagnostic discordance or limited local anaesthetic capacity. Genetics referral should offer pre-test counselling and explain implications for relatives. Same-day emergency referral is required for severe hypertension plus chest pain, pulmonary oedema, neurological deficit, seizure, acute kidney injury, hyperthermia, shock or rapidly changing blood pressure. Do not send an unstable patient to an outpatient clinic. In India, transfer planning should identify an ICU-capable hospital, endocrine and anaesthetic expertise, blood-product and vasoactive-drug access, and a safe transport team. If molecular testing or functional imaging is unaffordable or unavailable, this should shape sequencing and shared decisions but must not justify unsafe adrenal biopsy or unprepared surgery. Maintain local follow-up while tertiary appointments are pending.
Red Flags
Pheochromocytoma crisis may present with extreme or rapidly oscillating blood pressure, chest pain, pulmonary oedema, malignant arrhythmia, myocardial injury, severe headache, seizure, focal neurological deficit, hyperthermia, lactic acidosis, abdominal pain, acute kidney or liver injury, encephalopathy or circulatory collapse. A normal pressure at one moment does not exclude crisis because catecholamine cardiomyopathy can produce shock. Activate emergency and critical-care pathways, minimize physical tumour stimulation, obtain ECG, glucose, electrolytes and organ-injury assessment, and contact endocrine, anaesthesia and surgical teams early. Treating tachycardia with a beta-blocker before alpha-mediated vasoconstriction is controlled is a major avoidable hazard. Another red flag is any plan for adrenal biopsy, embolisation or operation before functional PPGL has been biochemically considered. During pregnancy, paroxysmal hypertension before 20 weeks, orthostatic hypotension, spells atypical for pre-eclampsia, an adrenal mass or cardiovascular collapse demands urgent joint obstetric-endocrine assessment; MRI is generally preferred when dedicated adrenal imaging is necessary, and radionuclide imaging is avoided. After blockade, syncope, severe orthostasis, worsening dyspnoea or oliguria may indicate excessive vasodilation or volume and cardiac problems. After surgery, persistent hypotension, hypoglycaemia, bleeding, adrenal insufficiency risk after bilateral or cortical-sparing procedures, and recurrent hypertension need immediate review. Months or years later, new spells, rising metanephrines, bone pain, weight loss or a new mass may indicate recurrence or metastasis. Histology labelled benign does not abolish long-term vigilance.
Indian Clinical Context
Indian practice spans centres with high-quality LC-MS/MS assays, genetic counselling, adrenal MRI, PET tracers and experienced endocrine anaesthesia, and settings where even correctly collected plasma metanephrines are difficult to obtain. Before testing, telephone the receiving laboratory about specimen posture, tube, handling, transport, assay and reference interval; a technically poor sample transported over distance can start a costly false-positive cascade. When supine plasma collection cannot be assured, properly collected 24-hour urinary fractionated metanephrines may be more feasible, but collection completeness and renal function still matter. Medicines common in local practice, including over-the-counter decongestants and unregulated weight-loss or stimulant products, should be documented without blame. Do not use imaging appearance or a fine-needle aspiration report to bypass hormone exclusion. Regional referral networks should identify where alpha blockade can be supervised and where experienced anaesthesia, arterial monitoring, ICU care and blood products are available. Generic doxazosin may be accessible where phenoxybenzamine is not; availability does not remove the need for titration and orthostatic monitoring. Salt and fluid preparation must account for hot climates, travel, heart failure and kidney disease. Genetic testing cost can constrain broad panels, so counselling can prioritize a phenotype-directed accredited panel while recording what was not tested. For pregnancy, early joint planning should include transport and neonatal capacity. International recommendations are evidence anchors, not Indian legal protocols. Current Indian labels, institutional formularies and local anaesthetic and surgical procedures govern actual treatment. Educational material should state uncertainty, avoid guaranteed cure claims and remain reviewed until organizational review.
NMC Competency Mapping
The NMC CBME Curriculum 2024 supplies relevant undergraduate anchors rather than a stand-alone authorization to manage PPGL independently. Physiology PY8.4 covers adrenal-hormone synthesis, secretion, physiological actions, altered secretion and adrenal function tests. Pharmacology competencies on autonomic drugs support understanding of alpha- and beta-adrenergic antagonism, adverse effects and the safety logic of alpha-before-beta sequencing. Medicine competencies on hypertension, endocrine presentations and emergency care support recognition of secondary hypertension and target-organ injury. Surgery teaching on adrenal and retroperitoneal disease provides principles of referral and operative care, while obstetric competencies support safe evaluation of hypertension in pregnancy. A graduating student should be able to take a focused spell and family history, recognize hypertensive emergency, interpret why metanephrines are preferred over random catecholamines, and explain why biochemical confirmation ordinarily precedes localisation. They should distinguish adrenal pheochromocytoma from extra-adrenal paraganglioma, identify hereditary clues, describe the danger of tumour biopsy and unprepared anaesthesia, and state that beta-blockade must never precede adequate alpha blockade. Learners should understand CT versus MRI selection, the purpose of functional imaging, and postoperative hypotension and hypoglycaemia. Competency attainment requires supervised clinical exposure, structured cases, pharmacology integration and assessment; reading this guide alone does not confer competence to select a blockade regimen, manage crisis, interpret variants, perform adrenalectomy or counsel a family. Local faculty should map exact session and assessment codes to the current curriculum edition.
Key Exam Pearls for NEET PG
Pheochromocytoma arises from adrenal chromaffin cells; an extra-adrenal chromaffin tumour is termed paraganglioma, and both may be hereditary. The classic headache-palpitations-sweating triad supports suspicion but its absence does not exclude disease. Preferred biochemical entry tests are plasma free metanephrines or urinary fractionated metanephrines because continuous intratumoural metabolism makes them more reliable than a random catecholamine level. Plasma sampling after quiet supine rest should use supine reference intervals. Borderline elevation invites review of posture, stress, renal function and drugs; strong elevation with a coherent phenotype carries greater probability. Localising imaging follows clear biochemical evidence in the usual stable pathway. CT is generally first-line for thorax, abdomen and pelvis; MRI is favoured when radiation should be limited, for pregnancy and for head-and-neck paraganglioma. Never biopsy an adrenal mass until pheochromocytoma has been excluded. Preoperative preparation usually lasts 7–14 days: alpha blockade first, restore contracted volume with salt and fluid when safe, then add beta blockade only for persistent tachycardia after adequate alpha blockade. Isolated beta blockade can cause unopposed alpha vasoconstriction and crisis. Minimally invasive adrenalectomy suits most localized adrenal tumours, while large invasive lesions often need open surgery. Postoperative hypotension and hypoglycaemia are high-yield complications. All patients should be offered shared decision-making about genetic testing. Metastatic behaviour is defined by tumour at nonchromaffin sites, not by a single reassuring histological feature, and long-term biochemical surveillance is required because recurrence may be delayed.
Frequently Asked Questions
Can pheochromocytoma be present when blood pressure is normal between attacks?
Yes. Catecholamine secretion and receptor responses vary, and some tumours are found through imaging or inherited-syndrome surveillance before sustained hypertension develops. Normal pressure at one visit does not exclude PPGL. Testing should be based on the whole clinical context and use properly collected plasma free or urinary fractionated metanephrines rather than symptoms alone.
Why must alpha blockade be established before a beta-blocker is added?
Catecholamines stimulate both alpha-mediated vasoconstriction and beta-mediated cardiac effects. Blocking beta receptors first can leave vasoconstriction unopposed, producing severe hypertension, pulmonary oedema or cardiovascular collapse. A beta-blocker is considered only after adequate alpha blockade when troublesome tachycardia persists, under specialist supervision.
Should an adrenal mass suspected to be pheochromocytoma undergo needle biopsy?
No, not until a functional pheochromocytoma has been excluded and a specialist team has shown that histology would change management. Needle placement or tumour manipulation can release catecholamines and provoke a life-threatening crisis. Biochemistry, adrenal imaging and multidisciplinary review usually provide the safer diagnostic sequence.
Does complete surgery mean lifelong follow-up is unnecessary?
No. Biochemical persistence, late recurrence, multifocal disease and metastatic progression can occur, particularly with hereditary or extra-adrenal tumours. Postoperative metanephrines establish a new baseline, and risk-adapted long-term or lifelong clinical and biochemical surveillance is planned with the endocrine and genetics team.
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