Acromegaly is a rare, slowly progressive systemic disorder caused by the excessive secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) after the fusion of the epiphyseal growth plates. It is characterized by somatic overgrowth, metabolic dysfunction, and multi-organ complications.

• Pituitary Adenomas (Primary Cause): Over 95% of cases result from a benign monoclonal pituitary somatotroph adenoma.
• Extrapituitary Causes (<5%): Ectopic GHRH secretion (e.g., bronchial carcinoids, pancreatic neuroendocrine tumors) or ectopic GH secretion.
• Genetic Conditions: Associated with familial syndromes such as Multiple Endocrine Neoplasia Type 1 (MEN1), Carney complex, McCune-Albright syndrome, and Familial Isolated Pituitary Adenomas (FIPA, AIP mutations).

At the cellular level, somatotroph adenomas autonomously secrete GH. GH stimulates the liver to produce IGF-1. Elevated circulating levels of both hormones promote cellular proliferation, protein synthesis, and bone and soft tissue hypertrophy. Chronically high GH levels antagonize insulin action, inducing hepatic gluconeogenesis and peripheral insulin resistance.

• Prevalence: Approximately 4 to 13 cases per 100,000 individuals.
• Incidence: 3 to 4 new cases per million annually.
• Age and Gender: Most commonly diagnosed in adults aged 30 to 50 years, with equal distribution between males and females.

Carrier of AIP, MEN1, PRKAR1A, or GNAS* gene mutations.

• Family history of pituitary adenomas.

• Vitals: Hypertension is frequently present.
• Inspection: Prognathism (protruding lower jaw), thick skin, and spade-like hands.
• Palpation: Enlarged thyroid gland (goiter); thickened, doughy skin.
• Auscultation: S3/S4 gallops or murmurs associated with cardiomegaly.

• Clinical Assessment: Identification of somatic changes and systemic comorbidities.
• Laboratory Testing: Screening of serum IGF-1 levels.
• Imaging Studies: Pituitary MRI to locate and size the adenoma.
• Functional Tests: Oral Glucose Tolerance Test (OGTT) for GH suppression.
• Biopsy Findings: Immunohistochemical staining showing GH positivity in resected pituitary tissue.
• Genetic Testing: Evaluated if syndromic features are present.
• Differential Diagnosis: Distinguishing from constitutional tall stature and hypothyroidism.