Acromegaly
Formal Definition
A systemic disorder caused by excess growth hormone (GH) in adults, almost always from a GH-secreting pituitary adenoma; characterized by progressive acral enlargement (hands, feet, jaw), coarse facial features, soft tissue overgrowth, insulin resistance, cardiovascular disease (hypertension, cardiomyopathy), sleep apnea, and increased risk of colorectal polyps and cancer; if onset before epiphyseal closure (in children) = gigantism.
How It's Used on the Ward
"Acromegaly" — the patient has been slowly changing over years: wedding ring no longer fits, shoe size increased, jaw grew forward, teeth spacing changed; colleagues notice the gradual transformation before the patient does.
Example
""52-year-old male with new diabetes, worsening sleep apnea, and carpal tunnel syndrome. Wife notes his voice has deepened and he has been getting increasingly sweaty. Physical exam: enlarged hands, frontal bossing, prognathism, macroglossia, skin tags. IGF-1 level 892 ng/mL (normal 18-60 age-adjusted). Oral glucose tolerance test with GH: nadir GH 45 ng/mL (fails to suppress below 1). MRI: 22mm pituitary macroadenoma. Diagnosis: acromegaly from GH-secreting pituitary adenoma.""
Clinical Context
Diagnosis: elevated IGF-1 (best screening test — reflects integrated GH secretion, not subject to pulsatile variation), then OGTT with GH measurement (GH fails to suppress below 1 ng/mL in acromegaly). Pituitary MRI to size and location of adenoma. Treatment: transsphenoidal surgery (first-line for most). Medical: somatostatin analogs (octreotide, lanreotide — first-line medical, shrink tumor + reduce GH), cabergoline (dopamine agonist, modest effect), pegvisomant (GH receptor antagonist — normalizes IGF-1 but does not shrink tumor). Radiation (SRS/IMRT) for residual disease after surgery. Complications: cardiovascular (hypertrophic cardiomyopathy, arrhythmias), respiratory (sleep apnea), metabolic (diabetes), colorectal cancer risk (colonoscopy recommended every 3-5 years), arthropathy.