ACROMEGALY &
GIGANTISM
BY : RITWAN BIN TAPENG
ACROMEGALY
DEFINITION
Chronic metabolic disorder in which
there is too much growth hormone and
the body tissue gradually enlarge
PATHOPHYSIOLOGY
Acromegaly is characterized by hypersecretion of growth hormone
(GH), which is caused by the existence of a secreting pituitary tumor
in more than 95% of acromegaly cases. Pituitary tumors are benign
adenomas and can be classified according to size (microadenomas
being less than 10 mm in diameter and macroadenomas being
greater than 10 mm in diameter).3,4 In rare instances, elevated GH
levels are caused by extra pituitary disorders. In either situation,
hypersecretion of GH in turn causes subsequent hepatic stimulation
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
COMPLICATIONS
Arthritis
Cardiovacular disease
Carpal tunnel syndrome
Colonic polyps
Glucose intolerance or diabetes
High blood pressure
Sleep apnea
Spinal cord compression
Uterine fibroids
Vision abnormalities
REFERENCES
http://onlinelibrary.wiley.co
http://www.harrisonspractice.com/practice/ub/view/Harrisons%20Practice/141312/2.0/acromegaly
http://www.patient.co.uk/doctor/Acromegaly.htm
http://www.acromegalyinfo.com/health-care-professional/epidemiology-pathophysiology.jsp
GIGANTISMDEFINITION
Abnormally large growth due to an excess
of growth hormone during childhood,
before the bone growth plates have
closed.
CAUSES
The 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)
Neurofibromatosis
If excess growth hormone occurs after normal bone growth has stopped, the condition 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) levels
Damage to the pituitary may lead to low levels of other hormones, including:
Cortisol
Estradiol (girls)
Testosterone (boys)
Thyroid hormone
TREATMENT
Medical 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
PROGNOSIS
Pituitary surgery is usually successful in limiting growth hormone 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
REFERENCES
http://health.nytimes.com/health/guides/disease/gigantism/overview.html
http://www.localhealth.com/article/gigantism/treatments
http://emedicine.medscape.com/article/925446-overview
http://www.scientificamerican.com/article.cfm?id=what-causes-gigantism-sandy-allen
http://www.yourhormones.info/endocrine_conditions/gigantism.aspx
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