Secondary hypertension is increasingly being recognised and identified as a cause of high blood pressure, distinct from essential hypertension. In many cases, symptomatology kickstarts a chain of investigations to rule out adrenal and renal causes. More often than not, there is a discordance between symptoms and investigation reports, which leads to frustration for both patient and physician. One clinical condition which may explain this discordance is pseudopheochromocytoma (pseudopheo). Dr. Sanjay Kalra describes the aetiopathogenesis, clinical features and management of pseudopheo, to help readers identify this syndrome in their practice.

Pseudopheochromocytoma

Pheochromocytomas (Pheo) are rare neuroendocrine tumours, most of which arise from chromaffin cells of the adrenal medulla. Extra adrenal tumours of a similar nature, which arise from autonomic neural ganglia, are termed as extra-adrenal pheos, or paragangliomas. The clinical manifestations of these lesions are due to the excess catecholamines that they secrete. The commonest presentation is paroxysmal hypertension, with or without the classic triad of symptoms (headache, sweating, palpitations). Sustained hypertension, heart failure, and pregnancy-induced hypertension are other presenting complaints.

Aetiopathogenesis

Pseudopheo is thought to be due to an increase in plasma dopamine levels, with normal adrenaline and noradrenaline concentrations. A more plausible hypothesis is that the cardiovascular response to catecholamines is amplified in pseudopheo, or that the adrenal release of adrenaline is enhanced as a response to (normal) sympathetic nervous stimulation.

It is possible that the adrenoreceptors have increased affinity to circulating catecholamines, and a sudden burst of catecholamine release is enough to trigger a pseudopheo attack. The sympathetic nervous system is thought to have an adrenal limb, which increases heart rate and cardiac output, and a neural limb, which increases peripheral resistance through vasoconstriction. Different limbs may predominate in different individuals, at varying times.

Symptoms and signs

Pseudopheo has been defined as having the following clinical features, by Mann et al.:

• Sudden-onset hypertensive paroxysms
• Chest pain, headache, lightheadedness, diaphoresis, nausea, palpitations, flushing, dyspnoea, weakness
• No emotional trigger
• H/o severe abuse/trauma
• Repressive coping style (coping with stress in an unemotional manner)
• Normal biochemistry
• Normal imaging

Differential diagnosis

These is a long list of differential diagnosis for pseudopheo, with pheochromocytoma being the commonest differential. Carcinoid syndrome, hypoglycaemia, hot flash, alcohol withdrawal, angina equivalent, migraine, labile hypertension and anxiety neurosis are some common differential diagnoses.

Management

1. The aim of management is to control blood pressure, and optimise psychological health.
2. A combination of α-blocker and β-blocker is the best choice for control of blood pressure. Prazosin and metoprolol combination, or carvedilol, or labetalol, are good options for use. Clonidine may also be used.
3. Sustained hypertension is best treated by following standard guidelines. It must be noted that ACE inhibitors, ARBs and calcium channel blocker are not effective in this condition.
4. Anxiolytics like alprazolam or clonazepam can be used to terminate paroxysms. Low-dose, selective serotonin reuptake inhibitors (citalopram, paroxetine) or tricyclic antidepressants (desipramine) can be used to reduce the frequency of paroxysms.
5. Psychological therapy must be used along with pharmacotherapy.
6. Regular monitoring is necessary, keeping in mind frequent and extreme fluctuation of blood pressure, and patient reluctance to accept the diagnosis.

Summary

Though pseudopheo is a rare disorder, physicians must be aware of its existence. A high index of clinical suspicion, along with rational therapy, can help avoid unnecessary investigations and treatment in affected patients.

Disclaimer- The views and opinions expressed in the article and videos are those of the speakers and do not necessarily reflect the official policy or position of M3 India.

The author, Dr. Sanjay Kalra is a leading Endocrinologist and the current President of the Endocrine Society of India.