The pituitary gland clinical case Flashcards
Pituitary diseases resulting from hypersecretion of GH, ACTH and prolactin (tumours)
GH - acromegaly
ACTH - Cushing’s disease
Prolactin - hyperprolactinaemia
Which hormones cause pituitary diseases due to hyposecretion of them
Anterior - (FSH/LH, GH, ACTH, TSH)
Posterior - Vasopressin
A space occupying pituitary disease can cause compression of what important structure?
Optic chiasm
Clinical features of acromegaly (gigantism) (6)
‘spade like’ hands (rings)
wide feet (shoes)
coarse facial features
thick lips & tongue
carpal tunnel syndrome - pressure on nerve in your wrist. It causes tingling, numbness and pain in your hand and fingers.
sweating
Complications associated with acromegaly (8)
Headache
Chiasmal compression
Diabetes M
Hypertension
Cardiomyopathy
Sleep apnoea
Colonic polyps + Cancer
Accelerated osteoarthritis
Diagnosis of acromegaly
GH suppression - - Failure to suppress GH is diagnostic of acromegaly when coupled with elevated IGF1 and clinical signs of excess growth hormone.
Is the patient’s vision normal?
Pituitary tumour on MRI
What causes acromegaly?
Increased secretion of GH from a pituitary tumour (99%) or hyperplasia
GH stimulates bone and soft tissue growth through increased secretion of insulin-like growth factor-1 (IGF-1)
What is cushing’s syndrome? Main cause?
Clinical state produced by chronic glucocorticoid excess + loss of normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis
Main cause is oral steroids
What is cushing’s disease?
Bilateral adrenal hyperplasia from an ACTH-secreting pituitary adenoma
Basically it is the collection of clinical symptoms and signs resulting from a pituitary tumour that causes excessive amounts of the hormone cortisol to be released by the adrenal glands.
Symptoms of cushing’s syndrome
Weight gain
mood change
Proximal myopathy – closer to trunk
Osteoporosis
Growth arrest in children
Clinical signs of cushing’s
Central obesity
Spontaneous purpura – small blood vessels burst, causing blood to pool under the skin
Moon face
Skin and muscle atrophy
Purple abdominal striae
Can cushing’s disease cause cushing syndrome
yes
Not all cases of cushing’s syndrome is caused by a pituitary tumour though
What is the action of the hormone cortisol (3)
Tissue breakdown – causes weakness of skin, muscle and bone
Sodium retention – may cause hypertension and heart failure
Insulin antagonism – may cause diabetes mellitus
What are 2 causes of ACTH dependent cushing’s syndrome (endogenous)
Pituitary tumour (Cushing’s disease)
Ectopic ACTH secretion (eg lung carcinoid)
What is ACTH
Adrenocorticotropic hormone - function of ACTH is to regulate levels of the steroid hormone cortisol released from the adrenal gland
What are 2 causes of ACTH independent cushing’s syndrome (non-endogenous)
Adrenal tumour (adenoma or carcinoma)
Corticosteroid therapy (eg for asthma, IBD)
What is the commonest hormonal disturbance of the pituitary
Hyperprolactinaemia
Function of prolactin hormone
stimulates lactation
What do raised levels of prolactin in the body cause?
Hypogonadism - diminished functional activity of the testes or the ovaries—that may result in diminished production of sex hormones.
Infertility
Osteoporosis
Causes of hyperprolactinaemia? Touch on physiological, pharmacological and pathological aspects
Physiological - pregnancy, lactation, stress
Pharmacological - DA depleting and DA anatgonist drugs (neuroleptics + anti-emetics), some antidepressants
Pathological - primary hypothyroidism, pituitary lesions
Hypopituitarism
Decrease in secretion of anterior pituitary hormones mainly but also posterior.
Which anterior pituitary hormones are affected in hypopituitarism
FSH/LH - gonadotropins
GH - growth hormone
ACTH - acts on adrenal - cortisol
TSH - thyroid stimulating hormone
Which posterior hormone is affected in hypopituitarism
vasopressin
Clinical features of hypopituitarism in Adults (7)
- Tiredness
- Weight gain
- Depression
- Reduced libido
- Menstrual problems
- Skin pallor
- Reduced body hair
Clinical features of hypopituitarism in Children (2)
- Reduced linear growth
* Delayed puberty
How do somatostatin analogues work in acromegaly
They improve tissue overgrowth, sweating, headache, sleep apnoea in most patients.
Normalise GH and IGF-1 levels in over 50% of patients.
Induce tumour shrinkage and reduce morbidity + mortality from acromegaly.
Adverse affects of Ocreotide and Lanreotide: Somatostatin analogues
Nausea
Cramps
Diarrhoea
Flatulence
Cholesterol gallstones occur in 20-30% (mostly asymptomatic)
Slow release preparations require monthly IM/SC injections
High cost
Treatment of Pituitary tumours causing hypersecretion
dopamine agonists
somatostatin analogues
GH receptor analogues
Treatment of Pituitary tumours causing hyposecretion
Hormone replacement: Cortisol, T4, sex steroids, GH
Desmopressin
