Acromegaly

Acromegaly is a rare, chronic, debilitating condition. Untreated, it not only causes significant morbidity but reduces life expectancy by about 10 years. The disease process is insidious and early presenting features may be non-specific (e.g. sweating, fatigue). Physicians, dentists and surgeons should consider this diagnosis if any of the more classically recognized features is present (e.g. dental malocclusion, symptoms of median nerve entrapment, sleep apnoea, type 2 diabetes mellitus without a family history). This is important because surgery remains the only hope of cure and surgical outcome varies widely with the size of the adenoma (90% or more for microadenomata versus 40–45% for macroadenomata, and even lower for those tumours that invade local structures), which, in turn, is related to the duration of the disease. The diagnosis of acromegaly is based on three key findings: clinical features, an elevated age-adjusted serum insulin-like growth factor 1 concentration and a serum growth hormone nadir greater than 0.4 μg/litre following a 75-g oral glucose challenge. Following biochemical confirmation of the disorder, MRI of the pituitary is performed to assess the size and regional anatomy in anticipation of future surgery. Medical control of acromegaly has improved significantly during the last decade with the introduction of long-acting somatostatin analogues and the relatively newer agent, pegvisomant. Radiation therapy is a potential adjuvant therapy for patients with residual disease, but may take 5–10 years to have its full effect.