Acromegaly — causes, symptoms, diagnosis, and treatment

Causes and mechanism

The most frequent cause of acromegaly is a benign GH-secreting tumor of the pituitary gland, known as a pituitary adenoma. Less commonly, GH excess can arise from rare tumors outside the pituitary or from hypothalamic pathology that stimulates GH release. The sustained elevation of GH and IGF-1 leads to progressive enlargement of skin, connective tissue and certain bones, along with metabolic disturbances such as insulin resistance.

Signs and symptoms

Changes usually appear slowly and may take years to be recognized. Typical features include enlargement of the hands and feet, widening of the jaw and spacing of the teeth, pronounced brow and nose, thickened skin, and increased soft-tissue volume of the tongue and lips. Patients commonly report joint pain, excessive sweating, fatigue, headache and changes in shoe or ring size. Systemic complications include sleep apnea, carpal tunnel syndrome, hypertension, cardiomyopathy, and impaired glucose tolerance or diabetes.

Diagnosis

Diagnosis relies on a combination of clinical assessment and biochemical testing. Measurement of serum IGF-1 is a sensitive screening test because IGF-1 levels remain elevated throughout the day. If IGF-1 is high or suspicion remains, dynamic testing with an oral glucose tolerance test is used to demonstrate the failure of GH to suppress. Imaging, most often magnetic resonance imaging (MRI) of the pituitary, identifies and characterizes an adenoma when present. Because the disorder evolves slowly, diagnosis is frequently delayed for many years.

Treatment and prognosis

Therapy aims to control GH/IGF-1 excess, reduce tumor mass when present, relieve symptoms and prevent or manage complications. First-line treatment for many patients is transsphenoidal surgical removal of a pituitary adenoma. Medical therapies include somatostatin analogs (which reduce GH secretion), GH receptor antagonists (which block GH action), and dopamine agonists in selected cases. Radiotherapy is an option when surgery and medication do not achieve control. With modern multidisciplinary care, many patients experience symptom improvement and reduced disease-related mortality, but long-term follow-up is necessary to monitor for recurrence and manage comorbid conditions.

History, prevalence and notable facts

Acromegaly is uncommon and is most often detected in middle-aged adults. Historical descriptions of the facial and physical changes date back centuries, but effective biochemical and surgical treatments developed during the 20th century greatly improved outcomes. Key distinctions—most importantly the difference between acromegaly and childhood gigantism—are based on whether excess GH occurs before or after the closure of growth plates. Early recognition improves the chances of restoring hormone balance and preventing long-term complications.

• Key points: caused mainly by pituitary adenoma; diagnosed by elevated IGF-1 and GH suppression testing; treated with surgery, medication, and sometimes radiotherapy.