Pituitary Gland Clinical Flashcards
What causes hyper secretion from pituitary gland
Pituitary adenoma = most common
Carcinoma / hypothalamic defects = rare
What are pituitary adenoma’s and what can they be associated with
Benign tumour
Sporadic
5% MEN1
How are they classified
Size - Micro <1cm - Macro >1cm Hormonal status - Secretory - Non-secretory
What is the most common pituitary adenoma and what does it cause
Prolactinoma = excess prolactin
- Galactorrhoea
- Menstrual disorder
What other types can you get and what does this lead too
GH secretory
- Acromegaly
- Gigantism in children
ACTH secreting
- Cushing’s
If large tumour what may it cause
Radiographic abnormalities
Optic chiasma compression = UL bitemporal hemianopia
Headache if fossa stretched
Elevated ICP
How do you investigate
Bloods - GH, prolactin, ACTH, FH, LSH, TFT
Visual field testing
MRI + contrast
How do you Rx
Hormone therapy
Transphenoidal surgery
RT
Surgery if visual abnormality or hypersecretoin (except if prolactinoma)
What are DDx
Pituitary hyperplasia Cranipharyngioma -LL Meningioma Brain mets Lymphoma Aneurysm
What is gigantism
Excess GH before epiphyseal growth plates fuse
What is acromegaly
Excess GH after growth plate sealed so no longitudinal growth as GH stimulates bone and soft tissue growth via IFF-1
Can still grow from soft tissue
What are causes
Pituitary adenoma= most common
Ectopic from tumour e.g. carcinoid
What are features of Acromegaly
Enlarged hands and feet Coarse facial features Sweating + headache = main features Oily skin Arthralgia Skin darkening Aconthosis nigrican Proximal muscle wasting Raised prolactin Pituitary tumour features
What are coarse facial features
Prominent forehead Eyebrows stick out Enlarged jaw Spaced out teeth Thick lips and tongue - macroglossia
What are features of raised prolactin
Gynaecomastia
Galactorrhoea
Amenorrhoea
What are features of pituitary tumour
Hypopituitary
Headache
Bitemporal hemianopia
What are complications of acromegaly
DM - GH anti-insulin Carpal tunnel Hypertension Cardiomyopathy Sleep apnoea Accerlerated OA Colonic polyps / cancer
What is 1st line blood test for diagnosis
Serum IGF-1
GH stimulates release
What do you do if IGF-1 raised
Oral glucose tolerance test if raised - give glucose
Glucose should suppress GH as low glucose stimulates GH
Acromgealy = fail to suppress
What other investigations
Bloods - glucose, Ca, phosphate will be increased
MRI to look for pituitary
AP pituitary bloods - prolactin, short synthetic, TSH and T4, LSH, FH and oestrodiol
Visual field + acuity
Why can’t you use GH levels
Fluctuates at different times
- Stress / exercise / sleep / other hormones
- Low BG increases GH
How do you treat
Trans-sphenoidal surgery for tumour = 1st line
Do others if IGF-1 begins to rise again
Somatostatin analogue (octreotide) - GHIH
GH receptor antagonist
Pituitary RT
What does somatostatin analogue do
Inhibits GH
Improves symptoms
Normalise GH and IGF-1 level
Induce tumour shrinkage
What are SE
Nausea / cramps / diarrhoea
Cholesterol gall stones
Monthly injections = expensive
What are GH receptor antagonists
Once daily S/C injection
Very effective in decreasing IGF-1 but doesn’t reduce tumour so ned surgery
When do you do RT
If failed surgical / medical
Will cause hypopituitary
What are DDX
Pregnancy
OA
Hypothyroid
What are physiological causes of hyperprolactin
Pregnancy
Lactation
Stress
What are pharmalogical causes
Da antagonists - Metoclopmaride / domperidone - Haloperidol / chlorpromazine Oestrogen Anti-depressants - SSRI Herbal
How does dopamine antagonist cause hyper-prolactin
Dopamine normally inhibits prolactin release (prolactin inhibiting hormone)
What are pathological causes of hyper-prolactin
Primary hypothyroid Prolactinoma PCOS Acromegaly Cushing
How do women present
Galactorrhoea Sore breasts Menstrual irregularity Infertility Decreased libido Weight gain
How do men present
Galactorrhoea Decreased facial hair Impotence Visual field defect - bitemporal hemianopia Extra-ocular weakness - Diplopia - Opthamoloplegia Optic atrophy Headache
How do you Dx prolactinoma
Serum prolactin
Do U+E, TFT, pregnancy test
Pituitary MRI
How do you treat microprolactinoma <10mm
Dopamine agonist
How do you treat macroprolacitnoma >10mm
Dopamine agonist
- Rapid fall in serum PRL
- Tumour shrinkage
- Visual improvement
What is advised if on dopamine agonist
Increase calcium and fit D
Can cause reduced oestrogen / testosterone
What should you be careful in
Pregnancy as may increase tumour size
1st Rx prolactinoma (not other pituitary tumours)
MEDICAL first
Consider surgery if fails
All other conditions =. surgery first
What are indications for treatment of hyperprolacitn
Fertility
Symptoms
Bone density maintenance
Existing or impending neurological S+S
What other investigations should be done for differentials
Prolactin LSH, FH, oestrodiol TFT bHCG Pregnancy test Drug history
How do you follow up agromegaly after surgery
Pituitary function test + OGTT 6 weeks after Serial MRI Regular IGF-1 Annual colonoscopy screening from age 50 EHCO
If patient presents with lethargy what would yo do
Baseline bloods
FBC, LFT, U+E, glucose, Ca, TFT
If these are normal what can you do
AP tests to look for pituitary cause
TSH, LH, oestrodiol, prolactin, IGF-1, random cortisol
MRI if abnormal
What causes hypopituituary
Compression by tumour Trauma Infection - TB Infiltration - Sarcoid Sheehan RT Immune
How do you Rx
Replace hormone
OSCE
Take Hx from this patient presenting with bitemporal hemianopia
What is pituitary apoplexy
Haemorrhage and or infarction of pituitary gland
What is often associated
Macroadenoma
What can occur
Headache Tachy / hypo / decreased GCS Hormone dysfunction - Give 200mg hydrocortisone stat as no cortisol - Only replace others once cortisol - Thyroxine - Sex hormones - GH Visual field disturbance
What do you do if suspect
CT head
Hormone profile
Visual field
