Acromegaly

Published on 05/05/2015 by admin

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Last modified 22/04/2025

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142 Acromegaly

Instruction

Examine this patient’s face.

This patient complains of excessive sweating; examine him.

Examine this patient’s hands.

Salient features

Examination

• On shaking hands there is excessive sweating: moist doughy, enveloping handshake.

• Large hands with broad palms, spatulate fingers; there is an increase in the ‘volume’ of the hands (Fig. 142.1).

• Look for evidence of carpal tunnel syndrome (tap over the flexor retinaculum for Tinel’s sign; see Fig. 76.1A).

Fig. 142.1 Acromegaly: hands with sausage-shaped fingers.

(With permission from Carey 2009.)

• Prominent supraorbital ridges

• Large nose and lips

• Protrusion of the lower jaw (prognathism); ask the patient to clench his teeth and note the malocclusion and splaying of the teeth (i.e. interdental separation)

• Ask the patient to show his tongue and look for macroglossia and for impressions of the teeth on the edges of the tongue (p. 829)

Proceed by testing:

Diagnosis

This patient has a protruding lower jaw, splaying of teeth and large spade-like hands (lesions), which are features of acromegaly caused by a pituitary tumour (aetiology).

Questions

Would you like to ask the patient a few questions?

Ask about any increase in size of shoes, gloves and hat, and whether the wedding ring is tight to wear.

Advanced-level questions

Mention some causes of macroglossia

• Amyloidosis

• Hypothyroidism

• Down syndrome.

How can this condition present?

One-third of patients notice a change in their features, one-third are noticed to have a change in their features by their GPs and the remaining third have symptoms such as excessive sweating and visual difficulties.

What are the indicators of disease activity?

• Symptoms such as headache, increase in size of ring, shoe or dentures

• Excessive sweating

• Hypertension

• Increased loss of visual fields.

How would you investigate this patient?

• Biochemical tests:

• Plasma insulin-like growth factor (IGF-1) levels (allows assessment of the efficacy of initial therapy and in the post-therapeutic period). Marked elevations establish the diagnosis

• When IGF-1 levels are only moderately elevated, diagnosis is confirmed by non-suppressibility of growth hormone levels to <1 µg/l after oral administration of 75 g glucose

• Serum thyroxine, prolactin, testosterone

• Evaluate pituitary function: static and dynamic tests

• Calcium levels (to exclude multiple endocrine neoplasia (MEN) type 1 syndrome).

Note: Random growth hormone level measurements are not useful because of pulsatile secretion.

• Radiography:

• Pituitary fossa (enlarged sella)

• Chest (cardiomegaly)

• Hand (terminal phalangeal ‘tufting’)

• Foot (terminal phalangeal ‘tufting’, lateral view shows increased thickness of the heel pad)

• MRI scan to evaluate the extent of tumour growth.

Remember: Unlike in Cushing’s disease and prolactinomas, the majority of the patients (~60%) with acromegaly have macroadenomas.

• Other investigations:

• Formal perimetry

• Obtain old photographs

• New photographs of face, torso, hands on the chest

• Triple stimulation test: if hypopituitarism is suspected.

What therapeutic options are available?

• Neurosurgical intervention, typically trans-sphenoidal, is the primary therapeutic choice for almost all patients. Diaphoresis and carpal tunnel syndrome often improve within 1 day of surgery. Although growth hormone levels fall immediately, insulin-like growth factor levels fall gradually.

• Radiation therapy is a primary treatment option for a few patients who have acromegaly but are not surgical candidates or when IGF-1 remains elevated after surgery because of residual tumour.

• The somatostatin receptor antagonist octreotide is valuable as adjunctive therapy to suppress growth hormone secretion while awaiting radiation. High doses of cabergoline (dopamine receptor antagonist) or treatment with somatostatin receptor ligands may improve the responsiveness to growth hormone in patients who otherwise have resistance to maximal doses of somatostatin receptor ligands

• Pegvisomant is a synthetic growth hormone receptor antagonist (the peptide is conjugated (pegylated) to polyethylene glycol to reduce renal clearance and immunogenicity) that lowers IGF-1 in >90% of patients, which is accompanied by clinical benefits (but no effect on tumour).

Remember: The aim of treatment should be symptomatic control and a growth hormone concentration of <5 mU/l.

Mention four common causes of death in such patients

• Cardiac failure

• Tumour expansion (mass effect and haemorrhages)

• Effects of hypertension

• Degenerative vascular disease.

Mention other conditions with excess growth hormone secretion

• MEN type 1: parathyroid hyperplasia, pituitary tumours and gut tumours

• McCune–Albright syndrome: polyostotic fibrous dysplasia, sexual precocity and café-au-lait spots

• Carney complex is an autosomal dominant disorder that consists of multicentric tumours in many organs, including myxomas in heart, breast and testes; pigmented skin lesions; and pigmented nodular hyperplasia.

In 1886 Pierre Marie (1853–1940) used the term acromegaly in describing two patients and reviewed eight previously published papers describing patients with presumed acromegaly (Marie P (1886) Sur deux cas d’acromegalie. Hypertrophie singulière non-congénitale des extrémités supérieures, inférieures et céphaliques. Rev Med 6:297–333). He also described Charcot–Marie–Tooth disease. In 1887 Minkowski deduced that acromegaly is related to pituitary tumour (Minkowski O (1887) Uber einen Fall von Akromegalie. Berl Klin Wochenschr 24:371–374).

In 1891 the New Syndenham Society published a translation of Marie’s original paper and a review by Souza-Leite of 48 patients (Marie P & de Souza-Leite JD (1891) Essays on Acromegaly. London: New Sydenham Society).

Fuller Albright, Professor of Endocrinology at Massachussetts General Hospital and Harvard Medical School, whose chief interest was calcium metabolism.

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