Adrenal: Phaeochromocytoma

Question 1

What is a pheochromocytoma?

Answer 1

Tumour of the adrenal glands that secrete unregulated/EXCESSIVE amounts of catecholamines (adrenaline)

Pheochromocytomas primarily arise from chromaffin cells in the adrenal medulla.

Question 2

What is the pathophysiology of pheochromocytoma?

Answer 2

Pheochromocytoma = tumour of the chromaffin cells of the adrenal medulla that secretes excessive amounts of adrenaline

Secretions tend to be in bursts, leading to intermittent symptoms.

Question 3

What percentage of pheochromocytoma cases are associated with genetic disorders?

Answer 3

30-40%

This includes conditions like neurofibromatosis type 1, Von Hippel-Lindau disease, and multiple endocrine neoplasia type 2 (MEN 2).

Question 4

What is the 10% rule of pheochromocytomas?

Answer 4

10% are bilateral, 10% are cancerous, 10% are outside of the adrenal gland

This rule highlights the atypical presentations of pheochromocytomas.

Question 5

What are some common symptoms of pheochromocytoma?

Answer 5

• Anxiety
• Sweating
• Headaches
• Tremor
• Palpitations
• Hypertension

Symptoms fluctuate based on adrenaline secretion, reflecting the fight or flight response.

Question 6

What tests are used to investigate pheochromocytoma?

Answer 6

• Plasma free metanephrines
• 24-hr urine catecholamines
• CT or MRI to identify tumour + genetic testing

Direct measurement of catecholamines is not reliable due to their fluctuating levels.

Question 7

What is the first-line management for pheochromocytoma?

Answer 7

Alpha blockers e.g. doxazosin or phenoxybenzamine and B-blockers

Beta blockers are only used once the patient is established on alpha blockers.

Question 8

What is the role of surgical removal in the management of pheochromocytoma?

Answer 8

Surgical removal of the tumour is a key management strategy

This is often necessary if the tumour is localized and operable.

Question 9

Fill in the blank: Pheochromocytomas secrete excessive amounts of _______.

Answer 9

adrenaline

This secretion leads to various symptoms associated with the fight or flight response.

Question 10

True or False: Pheochromocytomas can be cancerous.

Answer 10

True

According to the 10% rule, 10% of pheochromocytomas are found to be cancerous.

Question 11

What type of cancers are associated with MEN (Multiple endocrine neoplasia) types 1, 2A and 2B respectivly?

Answer 11