Acromegaly

In station 5 you may be asked to assess a 40 year old man with snoring

 

Alternative presentations for this case:

 

Headache and blurred vision on a background of diabetes and colonic polyps

Pain and tingling in hands with a background of hypertension

Thirst and polyuria (new diabetes)

Rectal bleeding

Newly diagnosed diabetic with hypertension

 

HISTORY (3 minutes)

 

Take a snoring history:

  • Timing questions- since when, getting worse, previous episodes
  • Do you stop breathing? If so, for how long?
  • Do you wake up choking?
  • Headache in the morning?
  • Fall asleep at work/in front of the TV?
  • Do you drive?
  • Reduced concentration?
  • Do you feel refreshed in the morning?
  • IMPACT on life
  • Collar size, weight, alcohol consumption

 

Specific acromegaly questions (it is often a spot diagnosis that the patient has acromegaly):

  1. CHANGE IN APPEARANCE – shoe size, hands, head, voice, changes in photo appearance, ill-fitting dentures
  2. DISEASE ACTIVITY- sweating, skin tags, BP, ankle swelling, acne, oily skin
  3. SOURCE- headache history and raised intracranial pressure questions, visual disturbance (bumping into things/loss of vision)
  4. COMPLICATIONS-
    1. Diabetes- thirst, polyuria, weight loss, infections
    2. CVS Risk factors- high BP, diabetes, smoking, high cholesterol, chest pain, palpitations, SOB, previous MI etc.
    3. Carpal tunnel- numbness or tingling hands?
    4. Osteoarthritis- joint pains?
    5. Gonadal- reduced sex drive, body hair, erection, testicles, periods, nipple leak?
    6. Bowels- change in bowel habit, rectal bleeding, pain, kidney stones, polyps
    7. Muscular- proximal weakness, difficulty getting out of a chair

Thyroid history (also causes Obstructive sleep apnoea [OSA])

Marfan’s history (also can cause OSA)

 

PMH

Dx

Fx

Sx

 

EXAMINATION (3 minutes)

 

Acromegaly examination:

 

  • Hands- large, sweaty?, pinch skin- it is thick, if carpal tunnel in history- examine for this and carpal tunnel release scars, is there evidence of capillary blood glucose testing, check the pulse
  • Test arms for proximal myopathy, whilst arms raised check for acanthosis nigricans and reduced armpit hair and skin tags
  • Offer to check BP
  • Test eye movements and visual fields (for bitemporal hemianopia). Offer to do fundoscopy if headache (optic nerve swelling or atrophy, features of diabetic and hypertensive retinopathy)
  • Look at face- hairy, spotty, oily, facial features- prominent supraorbital ridges, prognathism, big nose, tongue, ears, malocclusion of teeth. Don’t miss a surgical scar on the head!
  • Feel thyroid for goitre. Offer to check neck circumference if OSA history. Look at the neck for acanthosis nigricans
  • If OSA, examine nostrils and mouth and throat
  • Listen to heart, lungs, feel abdomen (hepatosplenomegaly and colonic masses). Look for gynaecomastia
  • Check feet for size and ankle swelling
  • Offer to check height and weight for BMI (if OSA)

 

ICE and Explanation (2 minutes)

 

  • Explain that breathing stops for short spells whilst asleep because of obstruction to flow of air down airway. Throat muscles go relaxed and floppy
  • Need to measure your height and weight, collar size, BP, oxygen levels
  • Need to do blood tests for thyroid function, diabetes, cholesterol
  • Will give you 2 questionnaires to complete and partner to complete too
  • Will arrange overnight pulse oximetry and tests of lung function
  • Will refer to Respiratory doctor
  • In the meantime: stop driving, stop smoking, weight loss, avoid alcohol and sedatives and sleeping tablets, don’t sleep on your back
  • Because you have mentioned x, and z, I would like to test you for a condition called acromegaly. Have you heard of it? The body makes too much growth hormone causing large extremities. Usually due to a small tumour in the pituitary gland making excess hormone. Can offer surgery to remove it and medicines to block it. Need to do some tests for this too and refer you to a hormone doctor. I will arrange a brain scan and refer you to an eye doctor (if visual symptoms and avoid driving if visual symptoms). Visual symptoms occur because the pituitary gland is pressing on nerves for vision.

 

 

 

VIVA

 

Obstructive Sleep Apnoea (OSA):

 

Questionnaires for OSA- Epworth sleepiness scale and sleep habit questionnaire (Epworth scale total score is 0-24, refer to Resp if: dangerous, score >9, COPD)

 

Overnight oximetry is looking at the frequency of 4% dips in oxygen saturations

 

Polysomnography to look at the AHI (apnoea/hyponoea index) moderate = >15 per hour

 

Management: stop driving, stop smoking, weight loss, avoid alcohol and sedatives and sleeping tablets, don’t sleep on your back.  Intraoral device if mild, CPAP if moderate

 

Test TFTs, HbA1c, lipid profile, ABG, Spirometry, BMI, BP

 

Risks of OSA- CVS and stroke disease, cor pulmonale and T2RF, Diabetes

 

 

Acromegaly

 

Acromegaly is caused by excess growth hormone secretion. The majority of cases are caused by a pituitary adenoma.

 

Tests for acromegaly:

 

  • Screen with IGF-1 (GH has a short t ½, GH is secreted in a pulsatile fashion, GH causes increased secretion of IGF-1, IGF1 correlates with GH secretion in the last 24 hours and is a static measurement, it is also used to monitor progression during follow-up
  • Diagnostic test = Oral glucose tolerance test (GH will not be suppressed, can in fact get a paradoxical rise. The principle is that insulin should cause a rise in IGF-1 leading to reduction in GH)
  • MRI pituitary fossa
  • Visual fields assessment
  • Test pituitary hormones (ACTH, cortisol, TFTs, LH, FSH, oestradiol, testosterone, prolactin)
  • BP and glucose and bone profile (hypercalcaemia of MEN1)
  • ECG, echo, CXR

 

Treatment of acromegaly:

 

  1. First choice = transphenoidal surgery to debulk
  2. RT (gamma knife) – adjuvant to surgery or if unfit for surgery
  3. Somatostatin analogues e.g. Octreotide, lanreotide (before or after surgery/RT) (GH secretion inhibited by somatostatin)
  4. Dopamine agonists e.g. bromocriptine, cabergoline less effective
  5. GH receptor antagonist – pegvisomant for somatostatin analogue resistant tumours
  6. Stop driving and optimise hypertension, diabetes etc.
  7. Yearly IGF1, GH, Prolactin, Visual fields, Vascular Assessment -ECG, CXR, glucose

 

Most physical features do not regress after treatment

Features of active disease can regress

Need colonoscopy surveillance every 3-5 years

Don’t forget that it can be part of MEN 1 so check Calcium level

Manage secondary diabetes and hypertension: 1 in 5 get diabetes as GH counters effects of insulin, 1 in 3 get hypertension

Can be associated with prolactin secretion too therefore patients can get galactorrhoea

 

Written by Dr Sarah Kennedy

 

Resources used include those listed in the references section of this webpage