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