Patient will present as → a 45-year-old woman presented with a 4-year history of progressive increase in body size, lactation and amenorrhoea, and a six-week history of worsening symptoms of heart failure. Physical examination showed coarse facial features, spade-like hands and feet, pitting pedal edema, galactorrhoea, and features of congestive cardiac failure. The chest radiograph showed gross cardiomegaly. On skull radiograph, destruction of the floor of the pituitary fossa was noted, with an erosion of the clinoid processes. She had hyperprolactinemia. Fasting and post-glucose growth hormone values were elevated.
Gigantism and acromegaly are usually caused by a pituitary adenoma that secretes excessive amounts of Growth Hormone (GH); rarely, they are caused by non-pituitary tumors that secrete GHRH
- Gigantism occurs if growth hormone hypersecretion begins in childhood, before the closure of the epiphyses
- Acromegaly involves growth hormone hypersecretion beginning in adulthood; a variety of bony and soft tissue abnormalities develop. Remember Acromegaly has an "A" for adulthood!
Diagnose by measuring IGF-1 and GH levels
Serum IGF-1 should be measured in patients with suspected acromegaly
- IGF-1 levels are typically substantially elevated (3-fold to 10-fold), and because IGF-1 levels do not fluctuate as GH levels do, they are the simplest way to assess GH hypersecretion. IGF-1 levels also can be used to monitor response to therapy
Plasma GH levels measured by radioimmunoassay are typically elevated
- Blood should be taken before the patient eats breakfast (basal state); in normal people, basal GH levels are < 5 ng/mL. Transient elevations of GH are normal and must be distinguished from pathologic hypersecretion. The degree of GH suppression after a glucose load remains the standard and thus should be measured in patients with elevated plasma GH
CNS imaging to detect a pituitary tumor
- CT or MRI of the head should be done to look for a tumor. If a tumor is not visible, excessive secretion of pituitary GH may be due to a non-CNS tumor producing excessive amounts of ectopic GHRH
Remove pituitary tumors surgically or using radiation therapy
- Sometimes pharmacologic suppression of GH secretion or activity: If tumors cannot be removed, give octreotide or lanreotide to suppress GH secretion
Increased growth hormone (GH)-releasing hormone (GHRH) from hypothalamic tumors
Ectopic GHRH from nonendocrine tumors
Pituitary adenomas or hyperplasia
Ectopic GH secretion by nonendocrine tumors
- Release of primary GH excess from the pituitary
- Increased GHRH secretion or hypothalamic dysregulation
- Hypothetically, the excessive production of IGF-binding protein, which prolongs the half-life of circulating IGF-I
Gigantism is more common than acromegaly
Acromegaly is typically associated with a delay in diagnosis
The mean age for onset of acromegaly is the second decade of life
Men develop acromegaly more frequently than women
Visual field defect
Sex steroid deficiency
- Symptoms due to local mass effects of an intracranial tumor
- Symptoms due to excess of GH/IGF-I
- Soft tissue swelling and enlargement of extremities
- Increase in ring and/or shoe size
- Coarsening of facial features
- Increased incidence of obstructive sleep apnea
- Increased incidence of glucose intolerance or frank diabetes mellitus, hypertension, and cardiovascular disease
- Hyperphosphatemia, hypercalcuria, and hypertriglyceridemia possible
- Increased incidence of congestive heart failure, which may be due to uncontrolled hypertension or to an intrinsic form of cardiomyopathy attributable to excess GH/IGF-I
- Increased incidence of colonic polyps
Routine imaging studies should be performed in all patients suspected of having acromegaly
GH is the most reliable biochemical indicator of acromegaly
Most patients investigated for acromegaly have a post glucose GH level that is intermediate (5-10 ng/mL)
Elevated IGF-I values in a patient suspected of acromegaly almost always indicate GH excess
Pharmacologic therapy is the first-line treatment for acromegaly
Radiation therapy is routinely indicated for most patients with acromegaly
For most patients with acromegaly, surgical removal of the pituitary gland tumor is the primary treatment
Somatostatin and dopamine analogues and GH receptor antagonists should be routinely instituted if surgery for acromegaly is required
- For most patients with acromegaly, surgical removal of the pituitary gland tumor should be considered the primary treatment.
- An imaging study should be performed at least 12 weeks post-surgery to determine whether any residual tumor tissue is present.
- Patients should be evaluated for any damage caused by the pituitary tumor and for the development of hypopituitarism.
- Medical therapy should be administered only to patients with persistent postoperative disease.