Pituitary gland clinical Flashcards
List 3 pituitary hyperfunction syndromes
Acromegaly,
Cushing’s disease
prolactinoma
Acromegaly and gigantism is an excess production of what pituitary hormone
GH
Cushing’s disease is an excess production of what pituitary hormone
ACTH
Prolactinoma is associated with an excess production of what
Prolactin
Symptoms (2) /signs (9) of acromegaly
Symptoms
- Fatigue
- Joint pain
- Sweating
- loss of sex drive
Signs
- Coarse facial features
- Large hands and feet
- Thick lips and tongue
- Carpal tunnel syndrome (pain, numbness and tingling in the hand + fingers)
- Skin change - thicker, skin tags,
- teeth separation
- deep voice
Complications of acromegaly (6)
Cardiac problems
-Left ventricular hypertrophy, cardiomyopathy, arrhythmia
Hypertension
Sleep apnoea
Carpal tunnel syndrome
Diabetes mellitus
Osteoarthritis
What syndrome is associated with/a complication of acromegaly
Carpal tunnel syndrome (pain, numbness, tingling of hand and fingers due to compression of median nerve in wrist)
Biochemical diagnosis of acromegaly (2)
Elevated serum insulin-like growth factor-1 (IGF-1) - screens for acromegaly and confirms diagnosis
Oral glucose tolerance test - indicates acromegaly if increasing plasma glucose doesn’t suppress GH, so lack of suppression of GH
Investigations of acromegaly (4)
Elevated serum insulin-like growth factor-1 (IGF-1)
Oral glucose tolerance test
Serum GH
Pituitary MRI
Cushing’s syndrome v Cushing’s disease
Cushing’s disease is under the umbrella of Cushing’s syndrome but the term is specific to a problem in the pituitary gland that leads to excess cortisol production (usually pituitary tumour)
Cushing’s syndrome refers to clinical manifestation of pathological hypercortisolism from any cause other than the pituitary (i.e. excess cortisol production)
Cortisol antagonises what anabolic hormone
Insulin
Symptoms (1) /signs (12) of cushing’s disease/ Cushing’s syndrome (they have the same clinical features)
+ specific sign in children
Symptoms
-mood swings - irritable, depressed
Signs
- weight gain - central obesity
- facial plethora (round + red - ‘MOON FACE’)
- buffalo hump - fat in back of neck and shoulders)
- proximal muscle weakness
- thin arms/legs compared to trunk
- decreased sex drive
- skin thinning/atrophy
- hirsutism
- osteoporosis
- purpura (red/purple patches on skin)
- purple striae
- easy bruisability
growth arrest in children
ACTH independent causes of Cushing’s syndrome (2)
Autonomous adrenal cortisol overproduction,
Long term corticosteroids, e.g. asthma, IBD
ACTH dependent causes of Cushing’s syndrome (2)
Pituitary adenoma (–> cushing’s disease)
rarely, by ectopic ACTH-secreting tumours (i.e. an ACTH secreting tumour that arises outwith the pituitary, e.g. lung carcinoid tumour)
What is moon face a sign of
Cushing’s syndrome
refers to a round and red puffy face
Investigations of Cushing’s syndrome (biochemical diagnostic investigations (3))
Late night (11pm) salivary cortisol - elevated in cushing’s, low in normal person
Overnight dexamethasone suppression test (then morning cortisol measured) - +ve test for cushing’s if morning cortisol elevated >50nanomol/l, should be suppressed in normal person
24hr urinary cortisol test - show high levels of cortisol >50micrograms/hr, lower than this in a normal person
What type of tumour is a prolactinoma
+ pathophysiology of it
Pituitary adenoma
benign lactotroph adenomas hyperexpressing and hypersecreting prolactin leading to secondary hypogonadism via its inhibitory effects on gonadotrophin-releasing hormone (from hypothalamus) and pituitary gonadotrophins
Symptoms/signs of a prolactinoma
- in women (3)
- in men (3)
- both (4)
Women
- amenorrhoea (absence of menstrual periods) or oligomenorrhoea (irregular periods)
- galactorrhoea (excessive production of milk)
- acne
- hirsutism (excessive body/facial hair)
Men
- erectile dysfunction
- gynaecomastia
- decreased body/facial hair
Both
- infertility
- loss of libido
- visual field abnormalities (possibly bitemporal hemianopia)
- osteoporosis
Causes of hyperprolactinaemia
- physiological causes (2)
- pharmacological causes (1)
- pathological causes (2)
physiological
- pregnancy/ breast feeding
- stress
Pharmacological
-Dopamine antagonists (dopamine usually inhibits prolactin secretion from AP)
Pathological
- primary hypothyroidism
- prolactinoma
Drugs that can cause hyperprolactinaemia (3)
Dopamine antagonists
Dopamine depleting agents
Oestrogens
Biochemical diagnosis of prolactinoma
Serum prolactin - elevated
Clinical features of hypopituitarism in adults (8)
Fatigue Weight gain Depression Reduced libido Impotence (erectile dysfunction) Amenorrhoea/ galactorrhoea Headache Cold intolerance
Clinical features of hypopituitarism in children (2)
Failure to thrive/short stature
Delayed puberty - lack of body hair, underdeveloped testes,
2 types of diabetes insipidus
Central diabetes insipidus (DI), -due to defective synthesis or release of ADH from the hypothalamo-pituitary axis;
Nephrogenic DI
-due to renal insensitivity to ADH
Clinical features of diabetes insipidus (2)
polydipsia (increased thirst/drinking)
polyuria - large volumes of hypotonic urine
Is diabetes insipidus associated with pituitary hypo or hyper function + why
Hypofunction
- as it involves defective release of ADH from the posterior pituitary
Hypopituiarism is a deficiency of what potential hormones
AP
-FSH/LH, GH, ACTH, TSH
PP
- vasopressin (ADH)
- oxytocin
Describe the consequences of a space occupying lesion in the pituitary region (imaging techniques,, visual field assessment).
Compresses the optic chiasm –> bitemporal hemianopia
Difference between functional and non-functional neoplasms of the endocrine system
Functional - hypersecreting hormones
Non-functional - non-secretory
Imaging investigation of a pituitary tumour
Pituitary MRI
Examination of someone with a pituitary tumour
Visual field assessment - bitemporal hemianopia (only if large enough to compress optic chiasm)
Treatment of a prolactinoma
Dopamine agonist, e.g. cabergoline
- decreases serum prolactin within hours
- shrinks tumour within weeks
Treatment of ACTH deficiency
Oral corticorticosteroids (hydrocortisone or prednisolone) since adrenal grands are not getting stimulated to produce steroid hormones
What is a pituitary apoplexy
Infarction of or haemorrhage into the pituitary gland
-initial sudden headache
+/- nausea/vomiting followed by rapidly worsening visual defect
Treatment of hypopituitarism
Hormone replacement of whatever hormone is deficient
Treatment of TH deficiency/hypothyroidism
Levothyroxine
Treatment of gonadotrophin-releasing hormone (GnRH) deficiency
- males
- females
Males
- testosterone if fertility not desired
- injectable gonadotrophin if fertility desired
Females
- oestrogen if fertility not desired
- injectable gonadotrophin if fertility desired
Treatment of GH deficiency
Recombinant GH (somatotropin)
Treatment of ADH deficiency (from posterior pituitary), i.e. central diabetes insipidus
Desmopressin ( synthetic analogue of antidiuretic hormone (ADH))
1st line treatment of all pituitary tumours except prolactinoma
Transphenoidal surgical resection
Treatment modalities of pituitary tumours (3)
Surgery - transphenoidal
Medication
Radiotherapy
Why is the use of pituitary radiotherapy declining
Acts slowly and can cause hypopituitarism if too strong
What differentiates micro and macroprolactinoma
Microprolactinoma <10mm
Pituitary hyperfunction most commonly due to what pathology
pituitary adenoma; carcinomas RARE
Histology of pituitary adenoma
Cells of same appearance as normal gland (but usually only one cell type seen, i.e. only acidophils or basophils)
Tumour is classed by what hormone it’s excessively producing
