AC DEFINITIONRO Chronic metabolic disorder in which there isM too much growth hormone and the bodyE tissue gradually enlargeGALY
PATHOPHYSIOLOGYAcromegaly is characterized by hypersecretion of growth hormone (GH),which is caused by the existence of a secreting pituitary tumor in more than95% of acromegaly cases. Pituitary tumors are benign adenomas and can beclassified according to size (microadenomas being less than 10 mm indiameter and macroadenomas being greater than 10 mm in diameter).3,4 Inrare instances, elevated GH levels are caused by extra pituitary disorders. Ineither situation, hypersecretion of GH in turn causes subsequent hepaticstimulation of insulin-like growth factor-1 (IGF-1).1
SYMPTOMS Body odor Carpal tunnel syndrome Decrease muscle strength ( weakness ) Easy fatique Enlarge feet Enlarge hands Enlarge glands in the skin ( sebaceous glands ) Enlarge jaw and tongue Excessive height Excessive sweating
SYMPTOMS ( cont… ) Headdache Hoarseness Joint pain Limited joint movement Sleep apnea Swelling of bony areas around a joint Thickening of skin, skin tags Widely spaced teeth Excess hair growth in females Weight gain
DIFFERENTIAL DIAGNOSIS Pseudoacromegaly Presence of similar acromegaloid features in the absence of elevated GH or IGF-I levels Physiologic growth spurt during puberty Familial tall stature or large hands and feet Myxedema
INVESTIGATION Visual field tests Assessment of other pituitary hormones: prolactin, adrenal, thyroid, and gonadal hormones MRI scan of pituitary and hypothalamus: more sensitive than CT scan CT scan: for lung, pancreatic, adrenal or ovarian tumours that may secrete ectopic growth hormone or GHRH Total body scintigraphy with radio-labelled OctreoScan® (somatostatin) to aid localisation of the tumour Cardiac assessment: electrocardiogram, echocardiogram
PROGNOSIS Pituitary surgery is successful in most patient, depending on the size of the tumor and the experience of the surgeon Without treatment the symptoms will get worse,and the risk of cardiovascular disease increase
GI DEFINITIONG Abnormally large growth due to an excess ofA growth hormone during childhood, before theN bone growth plates have closed.TISM
CAUSESThe most common cause of too much growth hormone release is a noncancerous(benign) tumor of the pituitary gland. Other causes include: Carney complex McCune-Albright syndrome (MAS) Multiple endocrine neoplasia type 1 (MEN-1) NeurofibromatosisIf excess growth hormone occurs after normal bone growth has stopped, thecondition is known as acromegaly.
SYMPTOMS Delayed puberty Double vision or difficulty with side (peripheral) vision Frontal bossing and a prominent jaw Headache Increased sweating Irregular periods (menstruation) Large hands and feet with thick fingers and toes Release of breast milk Thickening of the facial features Weakness
EXAMS & TESTS CT or MRI scan of the head showing pituitary tumor Failure to suppress serum growth hormone (GH) levels after an oral glucose challenge (maximum 75g) High prolactin levels Increased insulin growth factor-I (IGF-I) levelsDamage to the pituitary may lead to low levels of other hormones, including: Cortisol Estradiol (girls) Testosterone (boys) Thyroid hormone
TREATMENTMedical treatments of gigantism Medications may be used to reduce GH release, block the effects of GH, or prevent growth in stature. They include: Dopamine agonists, such as bromocriptine mesylate (Cycloset, Parlodel) and cabergoline (Dostinex), which reduce GH release GH antagonist, pegvisomant (Somavert), which blocks the effects of GH Sex hormone therapy, such as estrogen and testosterone, which may inhibit the growth of long bones Somatostatin analogs, such as octreotide (Sandostatin) and long-acting lanreotide (Somatuline Depot), which reduce GH release
TREATMENT ( cont… )Other treatments of gigantism Radiation of the pituitary gland to regulate GH. This is generally considered the least desirable treatment option because of its limited effectiveness and side effects that can include obesity, emotional impairment, and learning disabilities Surgery to remove a pituitary tumor, which is the treatment of choice for well-defined pituitary tumors
PROGNOSISPituitary surgery is usually successful in limiting growthhormone production.
COMPLICATIONS Delayed puberty Difficulty functioning in everyday life due to large size and unusual features Diminished vision or total vision loss Embarrassment, isolation, difficulties with relationships, and other social problems Hypothyroidism Severe chronic headaches Sleep apnea