Adrenocortical Neoplasms Flashcards
What is a phaeochromocytoma?
Catecholamine producing tumours that usually arise from the chromaffin cells of the adrenal medulla; derived from neural crest. Extra-adrenal in ~10% of cases.
What is a paraganglioma?
Extra-adrenal phaechromocytoma.
Also used to describe non-catecholamine-secreting tumours derived from parasympathetic paraganglia (e.g. carotid body chemodectomas).
Pattern of phaeochromocytoma secretion cf adrenal medulla?
Phaeochromocytoma: mainly secretes noradrenaline.
Adrenal medulla: mainly secretes adrenaline.
EXCEPT: familial phaeochromocytomas ==> may secrete large amounts of adrenaline.
Do phaechromocytomas show familail predisposition?
YES! Up to 30% of cases.
Percentage of HTN attributable to phaeochromocytomas?
0.2%
Conditions predisposing to familial phaeochromocytoma?
- Multiple endocrine neoplasia (MEN 2a/2b)
- von Hippel Lindau (VHL) syndrome
- Succinate dehydrogenase (mitochondrial enzyme) gene mutations
- Neurofibromatosis type 1
What is multiple endocrine neoplasia type 2a associated with?
- Medullary thyroid carcinoma
- Hyperparathyroidism
What is multiple endocrine neoplasia type 2b associated with?
- Medullary thyroid carcinoma
- Mucosal neuromas
Common clinical symptoms in patients with phaeochromocytoma?
COMMON =
i) Headache
ii) Sweating
iii) Palpitations
- CV: CP, dyspnoea (ischaemia / HF)
- GI: nausea, epigastric pain, constipation
- Neuropsychiatric tremor, weakness, anxiety
Clinical signs in patients w/ phaeochromocytoma?
- Pallor
- Tachycardia
- Hypertension
- Postural hypotension (due to reduced plasma volume)
Screening in suspected phaeochromocytoma?
- MEN type 2: measure serum calcium and calcitonin
- VHL: opthalmoscopy, MRI of posterior fossa and renal ultrasound
- Neurofibromatosis type 1: examine for neurofibromas, cafe-au-lait spots, axillary frecling
What is a paraganglioma?
Extra-adrenal phaechromocytoma.
Also used to describe non-catecholamine-secreting tumours derived from parasympathetic paraganglia (e.g. carotid body chemodectomas).
Pattern of phaeochromocytoma secretion cf adrenal medulla?
Phaeochromocytoma: mainly secretes noradrenaline.
Adrenal medulla: mainly secretes adrenaline.
EXCEPT: familial phaeochromocytomas ==> may secrete large amounts of adrenaline.
Do phaechromocytomas show familail predisposition?
YES! Up to 30% of cases.
Conditions predisposing to familial phaeochromocytoma?
- Multiple endocrine neoplasia (MEN 2a/2b)
- von Hippel Lindau (VHL) syndrome
- Succinate dehydrogenase (mitochondrial enzyme) gene mutations
- Neurofibromatosis type 1
What is multiple endocrine neoplasia type 2a associated with?
- Medullary thyroid carcinoma
- Hyperparathyroidism
What is multiple endocrine neoplasia type 2b associated with?
- Medullary thyroid carcinoma
- Mucosal neuromas
Common clinical symptoms in patients with phaeochromocytoma?
COMMON =
i) Headache
ii) Sweating
iii) Palpitations
- CV: CP, dyspnoea (ischaemia / HF)
- GI: nausea, epigastric pain, constipation
- Neuropsychiatric tremor, weakness, anxiety
Clinical signs in patients w/ phaeochromocytoma?
- Pallor
- Tachycardia
- Hypertension
- Postural hypotension (due to reduced plasma volume)
Ix in suspected phaeochromocytoma?
- 24h urinary catecholamines and metanephrines
- Plasma free metanephrines
- Imaging: CT / MRI
Screening in suspected phaeochromocytoma?
- MEN type 2: measure serum calcium and calcitonin
- VHL: opthalmoscopy, MRI of posterior fossa and renal ultrasound
- Neurofibromatosis type 1: examine for neurofibromas, cafe-au-lait spots, axillary frecling
Pre operative preparation in patients with phaeochromocytoma?
-alpha blocker (e.g. phenoxybenzamine 40-100mg daily ==> increase dose until normotensive + postural hypotension + nasal stuffiness)
-followed by B-blocker (e.g. propranolol NEVER pre alpha)
-rehydration
2-3 weks pre surgery
