Acromegaly

In Station 5 you may be asked to assess a patient with snoring, headaches, change in appearance, or newly diagnosed diabetes with hypertension.

1. Key History-Taking Points

Presenting Complaint — Snoring / Obstructive Sleep Apnoea

• Timing: since when, getting worse, previous episodes
• Apnoeic episodes: does breathing stop during sleep? For how long? (witnessed by partner?)
• Waking: waking up choking, gasping, or unrefreshed
• Morning headache (hypercapnia from nocturnal hypoventilation)
• Daytime somnolence: falling asleep at work, driving, or watching TV; Epworth Sleepiness Scale >9 = significant
• Concentration and memory
• Impact on life — work, relationships, quality of life
• Driving: must advise to stop driving if excessive daytime sleepiness
• Collar size, weight, alcohol consumption: aggravating factors for OSA

Acromegaly — Change in Appearance

• Change in shoe size, ring size, hat size — often noticed gradually over years
• Change in facial appearance — patient or family notice a change in photos?
• Voice change — deeper, coarser voice (macroglossia, laryngeal changes)
• Ill-fitting dentures — prognathism causing malocclusion

Acromegaly — Disease Activity

• Sweating: excess sweating (a marker of active disease)
• Skin tags (associated with colonic polyp risk)
• Acne, oily skin
• Ankle swelling (fluid retention from GH excess)

Acromegaly — Source (Pituitary Tumour)

• Headache: site, character, severity, duration — direct mass effect of pituitary adenoma
• Visual disturbance: bumping into things, loss of peripheral vision (bitemporal hemianopia from optic chiasm compression), blurring
• Avoid driving if any visual symptoms until formally assessed

Acromegaly — Complications

• Diabetes: thirst, polyuria, weight loss, recurrent infections (GH is counter-regulatory to insulin; 1 in 5 develop diabetes)
• Cardiovascular: hypertension, chest pain, palpitations, SOB, previous MI; full CVS risk factor history — smoking, hypercholesterolaemia (1 in 3 develop hypertension)
• Carpal tunnel syndrome: numbness or tingling in the hands, worse at night
• Osteoarthritis: joint pain, reduced mobility
• Gonadal dysfunction: reduced libido, reduced body hair, erectile dysfunction, testicular atrophy, menstrual irregularity, galactorrhoea/nipple discharge (co-secretion of prolactin)
• GI / colonic: change in bowel habit, rectal bleeding, abdominal pain, kidney stones (MEN1 hypercalcaemia); skin tags and colonic polyps increase colorectal cancer risk
• Proximal myopathy: difficulty rising from a chair, climbing stairs
• Thyroid: symptoms of hypo or hyperthyroidism (thyroid may enlarge; thyroid disease also causes OSA)

Past Medical, Drug & Family History

• PMH: diabetes, hypertension, colonic polyps, kidney stones, previous pituitary or head surgery
• Medications: current treatments for diabetes, hypertension; note any dopamine agonists or somatostatin analogues already prescribed
• Family history: MEN1 (parathyroid, pituitary, pancreatic tumours — remember to check calcium); pituitary tumours; acromegaly is rarely familial but MEN1 must be excluded
• Social: driving, occupation, alcohol

2. Key Examination Findings

Hands

• Large, spade-like hands
• Sweaty palms (active disease)
• Skin thickness: pinch dorsal hand skin — feels thick and doughy
• Carpal tunnel signs: if symptomatic — reduced sensation in median nerve distribution, weakness of APB, Tinel’s sign, Phalen’s test; look for carpal tunnel release scar
• Diabetic fingerprick marks
• Radial pulse: rate, rhythm, character (hypertension, cardiomegaly)

Arms

• Proximal myopathy: test shoulder abduction and elbow flexion against resistance; ask to raise arms above head
• Whilst arms raised:
  • Acanthosis nigricans in the axillae (insulin resistance)
  • Reduced axillary hair (hypogonadism)
  • Skin tags
• Offer to measure blood pressure (hypertension is common)

Eyes & Visual Fields

• Visual fields by confrontation: test for bitemporal hemianopia (optic chiasm compression from suprasellar extension of tumour)
• Eye movements: CN III, IV, VI palsies (cavernous sinus invasion)
• Fundoscopy if headache or visual symptoms: optic disc swelling (raised ICP) or atrophy, features of diabetic or hypertensive retinopathy

Face

• Prominent supraorbital ridges
• Prognathism: protruding lower jaw; teeth malocclusion
• Macroglossia: large tongue
• Large nose, large ears
• Coarse facial features, oily/acneiform skin, hirsutism
• Surgical scars on scalp or hairline: do not miss a transphenoidal or craniotomy scar

Neck

• Goitre: palpate thyroid
• Acanthosis nigricans in neck creases
• Offer to measure neck circumference if OSA history
• Inspect nostrils, mouth and oropharynx if OSA (macroglossia, tonsillar hypertrophy, narrow airway)

Chest, Abdomen & Feet

• Gynaecomastia (hyperprolactinaemia)
• Heart: listen for murmurs (cardiomegaly, cardiac failure)
• Lungs: auscultate (OSA-related cor pulmonale, cardiac failure)
• Abdomen: palpate for hepatosplenomegaly and colonic masses
• Feet: increased shoe size; ankle oedema (fluid retention)
• Offer to measure height and weight (BMI)

3. Specific Investigations

Acromegaly — Hormonal

• IGF-1 (screening test): GH has a short half-life and is secreted in a pulsatile fashion; IGF-1 reflects GH secretion over the preceding 24 hours and is a static, reproducible measurement; also used for monitoring during treatment
• Oral glucose tolerance test (OGTT) — diagnostic test: in health, glucose suppresses GH to <0.3 µg/L; in acromegaly, GH is not suppressed (and may paradoxically rise)
• Pituitary hormone profile: ACTH, cortisol (short synacthen), TFTs, LH, FSH, oestradiol/testosterone, prolactin (co-secretion is common; galactorrhoea if prolactin elevated)
• Calcium: hypercalcaemia suggests MEN1 (hyperparathyroidism)

Acromegaly — Imaging

• MRI pituitary fossa: identifies macroadenoma (>10 mm) or microadenoma; assesses suprasellar extension and proximity to optic chiasm
• Formal visual field assessment (Humphrey or Goldmann perimetry)
• ECG and echocardiogram: acromegalic cardiomyopathy, hypertensive heart disease
• CXR: cardiomegaly
• Bone profile: calcium, phosphate, ALP

Acromegaly — Complication Monitoring

• HbA1c and fasting glucose
• Fasting lipid profile
• Blood pressure
• Colonoscopy at diagnosis and every 3–5 years (colonic polyp and colorectal cancer surveillance)

OSA Investigations

• Epworth Sleepiness Scale (score 0–24; score >9 = refer to respiratory)
• Overnight pulse oximetry: frequency of 4% dips in oxygen saturation
• Polysomnography: apnoea-hypopnoea index (AHI); AHI >15/hour = moderate OSA
• TFTs, HbA1c, lipids, ABG, spirometry, BMI, BP

4. Management

Acromegaly

• First-line — Transphenoidal surgery: debulking or curative resection of pituitary adenoma; approach via nasal cavity; highly effective for microadenomas
• Radiotherapy (gamma knife / stereotactic): adjuvant if surgery incomplete or incomplete response; or primary treatment if patient unfit for surgery; GH levels fall slowly over years
• Somatostatin analogues: octreotide, lanreotide — inhibit GH secretion; used pre-operatively to shrink tumour or post-operatively if residual disease; given as monthly long-acting depot injections
• Dopamine agonists: bromocriptine, cabergoline — less effective than somatostatin analogues; useful if prolactin is also elevated
• GH receptor antagonist: pegvisomant — blocks peripheral GH action; for somatostatin analogue-resistant or intolerant patients; normalises IGF-1 effectively
• Stop driving if visual symptoms; optimise hypertension and diabetes

Ongoing Surveillance

• Annual IGF-1, GH, prolactin levels
• Annual visual fields assessment
• Annual vascular assessment — ECG, CXR, glucose
• Colonoscopy every 3–5 years
• Note: most structural features (prognathism, enlarged hands/feet) do not regress after treatment; features of active disease (sweating, soft tissue swelling) can regress

Manage Complications

• Secondary diabetes: metformin, GLP-1 analogues, insulin
• Hypertension: antihypertensives (ACE inhibitors or ARBs preferred if diabetes)
• Carpal tunnel syndrome: nocturnal splinting; surgical decompression if severe
• Hypogonadism: testosterone or oestrogen replacement as appropriate
• Screen and manage MEN1 if calcium elevated: refer to endocrinology
• Endocrine replacement if panhypopituitarism post-surgery: hydrocortisone, levothyroxine, sex hormone replacement, GH replacement if deficient post-treatment

OSA Management

• Lifestyle: stop driving, stop smoking, weight loss, avoid alcohol and sedatives/sleeping tablets, avoid supine sleeping position
• Intraoral mandibular advancement device: mild OSA
• CPAP (continuous positive airway pressure): moderate-to-severe OSA — titrated overnight in a sleep unit
• Address acromegaly as underlying cause — treatment of acromegaly often improves OSA significantly

Acromegaly Cheat Sheet