Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be talking to you about fear chromocytomas.

If you want to follow along with written notes on this topic, you can follow along at zero definals.com slash fear chromocytoma or in the endocrinology section of the zero definals medicine book.

Let's get straight into it. Let's start with some basic pathophysiology.

Adrenaline is produced by chromatin cells, which are in the adrenal glands, and a phyacromositoma is a tumor of

the chromophon cells that secretes unregulated and excessive amounts of adrenaline. Now, adrenaline is a tumour of the chromophon cells that secretes unregulated and excessive amounts of adrenaline.

Now, adrenaline is a catacolamine hormone and a neurotransmitter that stimulates the sympathetic

nervous system. So it's responsible for this fight-or-flight response. It increases arousal, it increases muscle tone, increases heart rate,

blood pressure, and all of the alert sort of symptoms that you experience when you're in a situation

of stress or danger. In patients with a phochromosatoma, the adrenaline tends to be secreted

in bursts, giving periods of worse symptoms, which are followed by more settled periods.

About 25% of fear chromocytomas are familial, and this is associated with the multiple endocrine neoplasia type 2 condition, or MEN2.

There's a 10% rule which is worth learning learning and this describes the pattern of the tumours.

So 10% are bilateral, 10% are cancerous and 10% occur outside the adrenal glands somewhere else in

the body.

How do you make a diagnosis?

Well, you can do two main investigations,

24-hour urine cataclyamines or plasma-free metanephrine.

Measuring the serum catacolamines is quite unreliable

as this will naturally fluctuate and it will be difficult to interpret the results.

So it's going to be high when the

tumor or the adrenal glands are naturally secreting adrenaline and low when the tumor or the adrenal glands

aren't secreting them. So having a high or low result doesn't either rule out or give you an

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