Acromegaly Flashcards
Define acromegaly
Constellation of signs & symptoms caused by hypersecretion of GH in adults
excess GH before puberty results in gigantism
Aetiology of acromegaly
causes main + rare
Most cases caused by GH-secreting pituitary adenoma
Rarely caused by excess GHRH causing somatotroph hyperplasia from hypothalamic ganglioneuroma, bronchial carcinoid or pancreatic tumours
Epidemiology of acromegaly
prevalence + age
RARE (5/1,000,000)
Affects age 40-50yrs
Presenting symptoms of acromegaly
8
- very gradual progression of symptoms over many years
- rings & shoes becoming tight
- increased sweating
- headaches
- carpal tunnel syndrome
- hypopituitary symptoms
- visual disturbances (due to compression of optic chiasm by tumour)
- hyperprolactinaemia
Signs of acromegaly on physical examination
5 groups
Hands Face Visual field loss Neck Feet
Prognosis with acromegaly
2
- Good prognosis with early diagnosis & treatment
- Physical changes are irreversible
Signs of acromegaly on physical examination - hands
4
Large spade like hands
Thick greasy skin
Carpel tunnel syndrome signs
Premature osteoarthritis
Signs of acromegaly on physical examination - face
9
Prominent eyebrow ridge Prominent cheeks Broad nose bridge Prominent nasolabial folds Thick lips Increased gap between teeth Large tongue Prognathism Husky resonant voice (due to thickening of vocal cords)
Signs of acromegaly on physical examination - visual field loss
Bitemporal superior quadrantopia progressing to bitemporal hemianopia
Signs of acromegaly on physical examination - neck
Multi nodular goitre
Signs of acromegaly on physical examination - feet
Enlarged
Hypopituitary symptoms
3
Hypogonadism
Hypothyroidism
Hypoadrenalism
Hyperprolactinaemia leads to…
3
Irregular periods
Decreased libido
Impotence
Investigations for acromegaly
4
Serum IGF-1
Oral glucose tolerance test
Pituitary function tests
MRI brain
Investigations for acromegaly - serum IGF 1
2
Useful screening test
GH stimulates IGF-1 secretion
Investigations for acromegaly - OGTT
Positive result = failure of GH suppression after 75g oral glucose load
Investigations for acromegaly - pituitary function tests
5
9am cortisol Free T4 & TSH LH & FSH Testoterone Prolactin
Investigations for acromegaly - MRI brain
Visualise pituitary adenoma
Management of acromegaly
3
Surgical
Radiotherapy
Medical
Management of acromegaly - surgical
Trans sphenoidal hypophysectomy
Management of acromegaly - radiotherapy
Adjunctive to surgery
Management of acromegaly - medical
general + 4
(if surgery contraindicated or refused)
Subcutaneous somatostatin analogues - e.g. octreotide, lanreotide
side effects: abdo pain, steatorrhoea, glucose intolerance, gallstones
Oral dopamine agonists - e.g. bromocriptine, cabergoline
side effects: N&V, constipation, postural hypotension, psychosis (rare)
GH antagonist - pegvisomant
Monitor GH & IGF-1 levels for disease control
Complications of acromegaly
7 groups
CVS Resp GI Reproductive Metabolic Psychological Complications of surgery
Complications of acromegaly - CVS
2
Cardiomegaly
Hypertension
Complications of acromegaly - respiratory
Obstructive sleep apnoea
Complications of acromegaly - GI
Colonic polyps
Complications of acromegaly - reproductive
Hyperprolactinaemia (in 30% cases)
Complications of acromegaly - metabolic
Hypercalcaemia Hyperphosphataemia Renal stones Diabetes mellitus Hypertriglyceridaemia
Complications of acromegaly - psychological
Depression Psychosis (from dopamine agonists)
Complications of acromegaly - complications of surgery
Nasoseptal perforation Hypopituitarism Adenoma recurrence CSF leak Infection
