• Clinical science



Acromegaly is a condition in which benign pituitary adenomas lead to an excess secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). In adults, whose epiphyseal plates are closed, the disease causes enlarged hands and feet, coarsened facial features, and pathological growth of internal organs. If the condition occurs in children, before epiphyseal plate closure, it is known as gigantism, which is discussed in a separate article. The first step in diagnosing acromegaly is to measure IGF-1 levels. Further testing includes an oral glucose tolerance test (OGTT) with assessment of GH levels, and evaluation of pituitary tumors via cranial MRI. Management consists of transsphenoidal adenomectomy for operable tumors, or GH-inhibiting medication and radiotherapy if surgery is contraindicated or unsuccessful. Adequate treatment is vital to reduce the risk of complications, such as cardiovascular disease and cerebral aneurysms, as these may considerably increase mortality.


  • Age of onset: 3rd decade of life (mean age at diagnosis usually 40–45 years) ) [1][2]

Epidemiological data refers to the US, unless otherwise specified.




Excess GH secretion before the conclusion of longitudinal growth (i.e., prior to epiphyseal plate closure) leads to pituitary gigantism with a possible height of ≥ 2 m. After epiphyseal plate closure, GH excess causes acromegaly, but no change in height!


Clinical features

Consider acromegaly in patients who report having had to increase hat, shoe, glove, and ring sizes in the past!



  • Hormone analysis
    • ↑ Serum IGF-1 concentration
      • Normal IGF-1 levels rule out acromegaly
    • If IGF-1: conduct OGTT with baseline GH and measure GH after 2 hours
      • → If GH suppressed to less than 1 μg/L (2 mU/l): acromegaly ruled out
      • → If GH not suppressed: confirmed acromegaly; conduct pituitary MRI
  • Pituitary MRI
    • Usually shows a visible mass: confirmed GH-secreting pituitary adenoma
    • If normal: screen for an extrapituitary cause (e.g., CT scan of the chest and abdomen, measure GHRH)
  • Tumor DNA analysis


Differential diagnoses

The differential diagnoses listed here are not exhaustive.


Transsphenoidal adenomectomy is the method of choice for treating acromegaly. In patients with inoperable tumors or unsuccessful surgery, medication and radiotherapy are indicated to reduce tumor size and limit the effects of GH and IGF-1.

Danger of hypopituitarism following surgery or radiotherapy!




We list the most important complications. The selection is not exhaustive.