Phaeochromocytoma

Question 1

what is a phaeochromocytoma?

Answer 1

• a rare neuroendocrine tumour arising from the adrenal medulla, the innermost layer of the adrenal gland
• most of these tumours are benign, with approximately 10% metastatic

Question 2

what is the aetiology of a phaeochromocytoma?

Answer 2

• sporadic
• multiple endocrine neoplasia type 2 (MEN2)
• von hippel-lindau (VHL) syndrome
• neurofibromatosis type 1 (NF1)
• familial paraganglioma-phaeochromocytoma (SDHx-related)

Question 3

where are most catecholamine-secreting tumours located?

Answer 3

• the vast majority are located in the abdomen and, more specifically, intra-adrenal
• the remaining are referred to as paragangliomas (e.g. arising from sympathetic/parasympathetic paraganglia)

Question 4

what cells do phaeochromocytomas arise from, and what do these cells produce?

Answer 4

chromaffin cells, whcih produce catecholamines (e.g. adrenaline, noradrenaline)

Question 5

what is the classic triad of symptoms associated with phaeochromocytoma?

Answer 5

• headache
• sweating
• palpitations

Question 6

what are the other symptoms of phaeochromocytoma?

Answer 6

• tremor
• weakness
• ‘impending sense of doom’
• pallor
• nausea
• blurring of vision
• polyuria
• polydipsia

Question 7

what are the signs on examination of phaeochromocytoma?

Answer 7

• hypertension
• orthostatic hypotension
• hypertensive retinopathy
• displaced and/or forceful apex beat (e.g. hypertensive cardiomyopathy)
• café-au-lait macules
• axillary freckling

Question 8

what are the investigations for phaeochromocytoma?

Answer 8

• ECG
• blood glucose
• urinalysis
• plasma free metanephrines (e.g. metanephrine, normetanephrine, 3-methoxytyramine)
• 24-hour urine fractionated metanephrines
• CT/MRI abdomen + pelvis
• PET/MIBG
• echocardiogram

Question 9

what is the management of phaeochromocytoma?

Answer 9

• alpha-blockers (e.g. phenoxybenzamine, doxazosin)
• beta-blockers (e.g. propranolol, metoprolol)
• adrenalectomy

Question 10

what are the long-term complications of phaeochromocytoma?

Answer 10

• ACS
• cardiomyopathy
• arrhythmia
• myocarditis
• pulmonary oedema
• ARDS
• renal infarction and/or failure
• hypertensive retinopathy
• stroke
• seizure
• pancreatitis
• ischaemic enterocolitis