Acromegaly

Abstract

Acromegaly is a rare, chronic, debilitating condition. Untreated, it causes significant morbidity and reduces life expectancy by about 10 years. The disease process is insidious, and early presenting features can be non-specific (e.g. sweating, fatigue). Physicians, dentists and surgeons should consider this diagnosis if any of the classically recognized features are present (e.g. dental malocclusion, carpal tunnel syndrome, sleep apnoea, type 2 diabetes mellitus without a family history). Timely diagnosis is important because surgery can be curative. Surgical outcomes vary widely depending on adenoma size (≥90% for pituitary microadenomas versus 40–45% for macroadenomas; lower for locally invasive tumours); this is in turn related to disease duration. Diagnosis is based on three key findings: clinical features, elevated age-adjusted serum insulin-like growth factor 1 and a serum growth hormone nadir >0.3 micrograms/litre after an oral glucose challenge. Once biochemically confirmed, magnetic resonance imaging of the pituitary is performed to assess the size and regional anatomy in anticipation of future surgery. Medical control of acromegaly has improved, with the introduction of long-acting somatostatin analogues and the growth hormone receptor antagonist pegvisomant. Radiation therapy is a potential adjuvant therapy for individuals with residual disease, but can take 5–10 years to have full effect.