pheochromocytoma

Question 1

define pheochromocytoma?

Answer 1

catecholamine - producing tumours that usually arise from chromaffin cells of the adrenal medulla

NOT ADENOMA- adenomas are cushing’s syndrome, conns, testosterone producing = tumours arising from cortex

Question 2

outline the different types of tumours for pheochromocytoma?

Answer 2

extra- adrenal in about 10%-> extra-adrenal phaemochromocytomas are referred to as paragangliomas

10% bilateral

10% are malignant

Question 3

outline the risk factors for pheochromocytoma?

Answer 3

Multiple endocrine neoplasia (MEN) syndrome type 2A and B

Von Hippel-Lindau (VHL) disease

neurofibromatosis type 1 (NF1)

succinate dehydrogenase (SDH) subunit B, C, and D gene mutations

Question 4

outline the epidemiology of pheochromocytoma?

Answer 4

• RARE

* <0.2% of cases of hypertensive patients

Question 5

what are the signs of pheochromocytoma?

Answer 5

• Hypertension 
• Postural hypotension 
• Pallor
• Tachycardia 
• Fever 
Weight loss

Question 6

what are the symptoms of pheochromocytoma?

Answer 6

• PAROXYSMAL episodes – comes in attacking manner
• Headache (due to malignant hypertension)
• Sweating

• Cardiorespiratory Symptoms 
        ○ Palpitations
	○ Chest pain 
	○ Dyspnoea 
• GI Symptoms 
        ○ Epigastric pain
	○ Nausea
	○ Constipation 
• Neuropsychiatric Symptoms 
	○ Weakness 
	○ Tremor 
        - Anxiety

Question 7

what are the signs of pheochromocytoma?

Answer 7

hypertension
postural hypotension
pallor
tachycardia
fever 
weight loss

Question 8

outline the investigations for pheochromocytoma?

Answer 8

1. 24 hr urine collection - check for catecholamine levels (and check for fractionated metanephrine/ vandillylmandelic acid levels)
   ○ NOTE: metanephrines are metabolites of adrenaline
2. Plasma free metanephrines and catecholamines
   ○ Most labs won’t be able to perform this
   ○ But acc more sensitive than urine
3. Genetic testing – done if under 50 mostly
   • Screen for associated conditions
   • Serum calcium and potassium + CBC
   • Tumour localisation (MRI or CT adrenal protocol not just CT abdoandpelvis)
   • Gallium-68 PET/CT scan
   I-MIBG scintigraphy (another way of visualising the tumour) - but really very rarely done nowadays

Question 9

Outline the treatment for pheochromocytoma?

Answer 9

1. Functional tests come back
2. alpha blockade
3. send for imaging
4. beta-blocker (if the pt develops a reflex tacchycardia so not all patients will require a betablockade)
5. Monitor the BP and slowly increase the alpha-blockade (few weeks)
6. finally surgical excision of adrenal gland

○ Retroperitoneal keyhole surgery
▪ Issue with other abdo viscera if done through the front
▪ Less pain for pt and shorter length of stay

○ Anterior and lateral approach keyhole – put pt on the side so all the other viscera fall away
▪ Some patients may not be able to lie on the front
▪ Most easy to convert into open so would do this if it looks very big and malignant

○ Open surgery through front or back (with back remove 12th rib)

7. Follow up
   ○ Surgery went
   ○ Annual follow up (serum or urine)
   Genetic testing if under 50

Question 10

describe the different methods of surgical intervention for pheochromocytoma ?

Answer 10

Retroperitoneal keyhole surgery

• Issue with other abdo viscera if done through the front
• Less pain for pt and shorter length of stay

Anterior and lateral approach keyhole – put pt on the side so all the other viscera fall away

• Some patients may not be able to lie on the front
• Most easy to convert into open so would do this if it looks very big and malignant

Open surgery through front or back (with back remove 12th rib)