Pituitary disease Flashcards
What are the different causes for raised prolactin?
Physiological: breast feeding, pregnancy, stress, sleep
Drugs: dopamine antagonists (metoclopramide), antipsychotics, antidepressants (TCAs and SSRIs)
Pathological: hypothyroidism, pituitary stalk lesion, prolactinoma (prolactin producing pit. adenoma)
What are the clinical signs and symptoms for hyperprolactinaemia in males/females?
Males:
- late presentation
- galactorrhea <30%
- visual field abnormality
- headache
- impotence
- anterior pit. malfunction
Females:
- early presentation
- galactorrhea 30-80%
- menstrual irregularity
- amenorrhoea
- infertility
What are the different investigations for prolactinoma?
- prolactin concentration
- MRI pituitary: pit. stalk, optic chiasm, microprolactinoma <1cm, macroprolactinoma >1cm
- visual field: bitemporal hemianopia
- pituitary function tests if other hormones affected
What is the medical treatment of prolactinoma?
Dopamine agonists:
- bromocriptine 2x a day orally
- quinagolide 1x a day orally
- cabergoline 2x a week orally (less side effects)
Results: prolactin normalised/tumour shrinkage
What is acromegaly?
GH excess due to somatrophadenoma, which stimulates IGF1 = mediator of GH actions
What are the features of acromegaly?
- giant if before epiphyseal fusion
- thickened soft tissues (skin/jaw/hands)
- HTN/cardiac failure
- headaches
- snoring/sleep disturbance
- DM
- local pituitary affects: visual field, hypopituitarism
- early CV death
What investigations are involved in the diagnosis of acromegaly?
- IGF1
- GTT
- visual field
- CT/MRI pituitary
- pituitary function tests
What is the treatment of acromegaly?
pituitary surgery than retest GTT and if still >11g/l needs dopamine agonists:
-carbegoline/ocreotide/pegvisomant
What is cushings syndrome? what is cushings disease?
Excess cortisol/mineralocorticoids/androgen
-cushings disease is specifically due to an excess of ACTH
What symptoms and signs are seen in cushings syndrome?
Excess cortisol:
- protein loss = myopathy/wasting, osteoporosis, thin skin (bruising)
- altered carb/lipid metabolism = DM/obesity
- altered psyches = psychosis/depression
Excess mineralocorticoid = hypertension and oedema (conjunctival oedema)
Excess androgen = virilism, hirsutism, acne, oligo/amernorrhea (frontal balding in women)
How is cushings tested for?
Dexamethasone suppression test
Screening:
- overnight 1mg DST = if cortisol <50nmol/l next morning is normal, if cortisol >100nmol/L is abnormal
- urine free cortisol <250 = normal
- cortisol/creatinine ratio <25 = normal
- diurnal cortisol variation
measure ACTH to see whether it is a pituitary cause or ectopic (that produces ACTH)
Diagnosis: 2 day 2mg DST
- <50nmol/L after last dose = normal
- suppress an adenoma 50%
- won’t suppress an ectopic
What is the epidemiology of cushings syndrome?
rare, commoner in women 20-40yrs
What are the different causes of cushings syndrome? split into 4 groups
Pituitary adenoma 80%+
Adenoma adrenal gland: benign/malignant
Ectopic: thymus, lung, pancreas (paraneoplastic secretes ACTH)
Pseudo: alcohol, depression, long term steroid medication (causes adrenal atrophy)
Describe the management of iatrogenic cushings syndrome?
Patients are unable to respond to stress and need extra doses if ill/surgery
- can’t stop suddenly
- gradual withdrawal steroid
Treatment of cushings syndrome if:
- pituitary
- adrenal
- ectopic
What drug treatment is available?
Pituitary:
-hypophysectomy and if recurs external radiotherapy
Adrenal:
-adrenalectomy
Ectopic:
-remove source or bilateral adrenalectomy
Drug treatment:
- metyrapone (if other treatments fail or whilst waiting for radiotherapy to work, S/E common)
- ketoconazole
- pasireotide (new somatostatin analogue)
What affects does pan-hypopituitarism cause due to the
- anterior pituitary
- posterior pituitary
Anterior pituitary:
- growth failure
- hypothyroid
- hypogonadism
- hypoadrenalism
Posterior pituitary:
-Diabetes insipidus
List causes of pan-hypopituitarism
¥ Pituitary Tumours
¥ Secondary metastatic lesions
Ð lung, breast
¥ Local brain tumours
Ð Astrocytoma, meningioma, glioma
¥ Granulomatous diseases
Ð TB, Histiocytosis X, sarcoidosis
¥ Vascular diseases
Ð Polyarteritis
¥ Trauma
Ð road accidents, skull fractures
¥ Hypothalamic diseases
Ð Syphilis, meningitis
¥ Iatrogenic; surgery
¥ Autoimmune;Sheenan – post pregnancy
Infection; meningitis
What are the symptoms and signs of pan-hypopituitarism?
¥ Menstrual irregularities (F) ¥ Infertility, impotence ¥ Gynaecomastia (M) ¥ Abdominal obesity ¥ Loss of facial hair (M) ¥ Loss of axillary and pubic hair (M&F) ¥ Dry skin and hair ¥ Hypothyroid faces ¥ growth retardation (children)
How is pan-hypopituitarism tested for?
Baseline pituitary function tests: ¥ fT4, TSH ¥ Oestradiol/Testosterone, LH FSH ¥ GH, IGF-1 ¥ Prolactin
How is pan-hypopituitarism treated?
¥ Thyroxine 100-150mcg/day
¥ Hydrocortisone 10-25 mg/day (am/pm)
¥ ADH Desmospray (nasal) or tablets
¥ GH nightly sc
¥ Sex Steroids Oest/prog pill for F. Testosterone for males
Always give hydrocortison first before thyroxine otherwise adrenal crisis may precipitate
How is testesterone replaced in pan-hypopituitarism? what are the risks?
¥ IM injection every 3-4 weeks (sustanon)
¥ Skin gel (testogel, tostram)
¥ Prolonged IM injection 10-14 wks (nebido)
¥ (Oral tablets (restandol))
Risks:
¥ Prostate Enlargement. Does NOT cause prostate cancer but may make it grow - monitor PR exam and PSA
¥ Polycythaemia- monitor FBC
¥ Hepatitis (only for oral tablets)- monitor LFTs
what is cranial diabetes insipidus? what is nephrogenic?
Cranial - lack secretion ADH (vasopressin)
Nephrogenic - renal resistance to ADH
what causes exist for cranial diabetes insipidus?
¥ Familial
Ð isolated in most cases
Ð DIDMOAD (DI, DM, optic atrophy, deaf)
¥ Acquired
Ð Idiopathic in 50%
Ð Trauma; road accidents, surgery, skull fracture
¥ RARE
Ð Tumour, sarcoid, ext irradiation, meningitis
What is the treatment for cranial diabetes insipidus?
¥ Desmospray
Ð nasally; 10- 60 mcg/day
¥ Desmopressin oral tablets
Ð 100-1000mcg per day
¥ Desmopressin sublingual tablets
- 60 – 360 mcg per day
¥ Desmopressin injection
Ð 1-2mcg IM per day
