Phaeochromoytomas (pheochromocytomas), often known as ‘phaeos’ (‘fee-ohs’), are rare tumours of the adrenal gland which develop in the inner section of the gland called the medulla. Similar tumours can arise from sites other than the adrenal gland and these are called extra-adrenal paragangliomas.
The body has two walnut-sized adrenal glands, sitting on top of each of the kidneys (‘adrenal’ means next to the kidney). Even though the glands are small they are important as they produce several essential hormones. The medulla (the area of the adrenal gland from which phaeos arise) produces a number of hormones called catecholamines, mainly adrenaline (epinephrine) and noradrenaline (norepinephrine). These hormones help the body deal with maintaining blood pressure, deal with sudden stress or threats. Phaeos may produce excessive amounts of these hormones, causing a variety of symptoms that can affect the whole body.
What is known about these tumours?
- This type of tumour is rare occurring in 1 per 100 000 people per year
- The majority (approximately 90% or 9 out of 10) are benign tumours (i.e. not cancer)
- Over 80% (8 in 10 cases) arise in the adrenal glands
- The most common age for diagnosis is between the ages of 30-60 years of age, although 10% arise in children
- There is no sex difference or racial disposition
- Tumours occurring in children are more likely to be related to an inherited condition than those occurring in adults.
Is there a genetic link?
- The majority of these tumours are not linked to a genetic condition and are therefore known as ‘sporadic’ tumours
- Approximately 25% (1 in 4 cases) are related to inheriting a gene change which leads to an increased risk of developing phaeochromocytoma
- The inherited forms can occur in syndromes, including multiple endocrine neoplasia 2 (MEN2), neurofibromatosis (NF) and von-hippel lindau syndrome (VHL)
- There are families who develop phaeos with paragangliomas due to a very rare change in the succinate dehydrogenase (SDH) gene. Learn more about hereditary SDH disorders.
What are the symptoms of phaeochromocytomas?
Phaeos can cause a wide variety of symptoms which are mainly related to the release by the tumour of excessive amounts of hormone, mainly adrenaline and noradrenaline. Symptoms can occur intermittently often in episodes lasting only 15 minutes and may include some or all of the following:
- Facial paleness (pallor)
- Excessive sweating
- Racing heart rate (palpitations)
- Panic attacks/ sense of doom
- Weight loss
- Heat intolerance
- High (and rarely low) blood pressure (sustained or episodic)
- Nausea (with or without vomiting)
Many of the symptoms listed above are related to the high blood pressure (hypertension) that can be caused due to this condition. It is thought one case of hypertension in every 1000-2000 patients is due to phaeochromocytoma. Hypertension in patients with undiagnosed phaeos can be very difficult to control; however, once a diagnosis is made, special drugs are available to help to control it.
For further detailed information on Phaeochromocytomas and Paragangliomas please read the AMEND patient information booklet which was produced in March 2012 in collaboration with the NET Patient Foundation:
Phaeochromotyomas and Paragangliomas (1.41 MB). We recommend that you discuss the content of this booklet with your specialist - it is not for use in self-diagnosis, and not all of the information it contains may be relevant to you.
Author: Jo Grey, AMEND CEO, with the help of the AMEND Medical Advisory Team