Acromegaly + Phaeochromocytoma Flashcards
1
Q
Definition of acromegaly
A
A multi systemic and progressive condition caused by excessive secretion of growth hormone.
2
Q
Cause of acromegaly
A
- Pituitary somatotroph adenoma (95-99%)
- Rarely ectopic secretion from neuroendocrine tumours
3
Q
Risk factors for acromegaly
A
- MEN 1: pituitary adenoma, primary hyperparathyroidism, and pancreatic neuroendocrine tumours
- McCune-Albright syndrome
4
Q
Symptoms of acromegaly
A
- Visual disturbance
- Headaches
- Rings and shoes are tight
- Polyuria and polydipsia (due to T2DM)
- Tingling in hands: carpal tunnel syndrome
- Galactorrhoea: raised prolactin is seen in over 20% of cases
5
Q
Signs of acromegaly
A
- Bitemporal hemianopia: due to compression of optic chiasm
- Facial features:
- Prominent jaw and supra orbital ridge
- Coarse facial apearance
- Prognathism: protrusion of the lower jaw
- Splaying of teeth
- Macroglossia: large tongue
- Spade-like hands
- Sweaty palms and oily skin
- Hypertension
6
Q
Investigations for acromegaly
A
- Bedside:
- ECG: can cause cardiomyopathy and heart failure
- Bloods:
- Insulin-like growth factor 1: first line investigation and raised in disease
- Oral glucose tolerance test: a glucose load should cause suppression of GH normally. In acromegaly, there is failure of GH suppression.
- Imaging:
- Pituitary MRI: visualisation of pituitary adenoma
- CT chest, abdomen and pelvis: very rarely can be due to an ectopic source
- Special tests:
- Visual field testing
7
Q
Management of acromegaly
A
- First line:
- Surgery: transphenoidal resection of pituitary
- Second line:
- Medical: dopamine agonists (eg cabergoline) in mild disease and somatostatin analogues (eg octerotide) in severe disease. Pegvisomant is a GH antagonist which is sometimes used, although very expensive
- Third line:
- Radiotherapy: reserved for patients who are refractory to medical and surgical treatment
8
Q
Complications of acromeglay
A
- Cardiac
- Hypertension
- Cardiomyopathy
- Heart failure
- Respiratory
- Obstructive sleep apnoea
- Neurological
- Carpal tunnel syndrome
- Proximal mypoathy
- Endocine
- T2DM
- Panhypopituitarism
- Gastrointestinal
- Colorectal cancer
9
Q
What is a pheochormocytoma?
A
A rare tumour (usually benign) arising from chromaffin cells in the adrenal medulla resulting in the overproduction of catecholamines.
10
Q
Which genetic conditions are linked to pheochromocytoma?
A
- MEN 2A: phaeochromocytoma, medullary thyroid cancer, primary hyperparathyroidism
- MEN 2B: phaeochromocytoma, medullary thyroid cancer, marfanoid habits
- Von-Hippel-Lindau syndrome: phaeochromocytoma, renal cell carcinoma, cerebellar hemangioblastoma
- Neurofibromatosis 1: phaeochromocytoma and skin changes eg café-au lait spots and neurofibromas
11
Q
Describe the rule of 10 seen in phaeochromocytomas
A
- 10% extra-adrenal (paraganglioma)
- 10% bilateral
- 10% malignant
- 10% familial
12
Q
Symptoms of phaeochromocytoma
A
- Episodic headache
- Palpitations
- Anxiety
- Sweating
13
Q
Signs in phaeochromocytoma
A
- Hypertension: present in 90% of cases and usually refractory to treatment
- Tachycardia
- Hypertensive retinopathy
14
Q
Primary investigations in phaeochromocytoma
A
- 24 hour urinary metanephrine collection: elevated
- Plasma-free metanephrines: elevated
- CT abdomen and pelvis: if there is biochemical evidence of a phaeochromocytoma, then CT imaging can be performed to look at the adrenals
15
Q
First line management of phaeochromocytoma
A
- Peri-operative: initial alpha blockade (eg phenoxybenzamine) followed by beta blockade (eg propanolol); 7 - 14 days preoperatively
- Surgical: definitive management with laparoscopic adrenalectomy
