Non-functioning adenomas, prolactinomas and acromegaly Flashcards
What are the definitions of microadenoma and macroadenoma?
Microadenoma: <1cm
Macroadenoma: >1cm
What can a large non functioning pituitary adenoma cause?
Compression on optic chiasm
Compression of cranial nerves 3,4 and 6 - commonly abducens which controls lateral eye movement causing an inward squint
What can an atrophic non-functioning pituitary tumour cause?
Hypoadrenalism Hypothyroidism Hypogonadism - amenorrhoea, ED DI GH deficiency
What will a pituitary adenoma do to the visual field?
Bitemporal hemaniopa - peripheral vision
What will a lack of dopamine do to the levels of prolacin?
Increased
What are the physiological causes of raised prolactin?
Breast feeding
Pregnancy
Stress
Sleep
What are the pharmacological causes of a raised prolactin?
Dopamine antagonists - metoclopramide Antipsychotics - phenothiazines Antidepressants - TCA, SSRIs Oestreogen Coccaine
What are pathological causes of raised prolactin?
Hypothyroidism
Stalk lesion - iatrogenic, trauma
Prolactinoma
Over what level of serum prolacin would you suspect a prolactinoma?
5000
What are the clinical signs and symptoms of a prolactinoma in females?
Galactorrhoea
Menstrual irregularity
Ammenorrhoea
Infertility
What are the clinical signs and symptoms of a prolactinoma in males?
Impotence
Visual field abnormal
Headache
Ant pit malfunction
What are the investigations for a prolactinoma?
Serum prolactin conc too high MRI pituitary (microprolactinoma, macroprolactinoma, pituitary stalk, optic chiasm) Visual fields (bitemporal hemianopia not homonymous hemianopia) Pit function tests
What are the treatments for a prolactinoma?
Dopamine agonists:
Cabergoline
Quinagolide
What are the S/E for dopamine agonists?
N+V
Low mood
Possible fibrosis
What clinical manifestations can result from acromegaly?
Giant (if before epiphyseal fusion) Thickened soft tissues (skin, large jaw, sweaty, large hands and nose) Sleep apnoea Hypertension and cardiac failure Headaches DM Pituitary - visual fields, hypopituitarism) Early CV death Colonic polyps
What type of headache with acromegaly cause?
Vascular effects due to increased dynamic blood flow through vessels
How is acromegaly diagnosed?
Too much IGF-1
GTT suppression test, in acromegaly GH will stay unchanged or will undergo a paradoxical rise
Visual field
CT/MRI pituitary scan
What surgical route is commonly utilised for a GH tumour?
Transsphenoidal - through nose into sphenoid sinus and through sphenoid bone
What is the treatment for acromegaly?
Pituitary surgery
External radiation to pituitary fossa
Retest GTT
What will a GTT GH of above 1 warrant after surgery has been performed?
Drugs
Radiotherapy
Repeat surgery
What is the commonest drug used for acromegaly?
Somatostatin analogues - sandostatin LAR
What are the effects of sandostatin?
Reduces GH in most patients
Tumour shrinkage
Usage pre-op to relieve headache
What are the S/E to somatostatin analogues?
Local stinging Flatulence Diarrhoea Abdominal pains Gallstones
Why can dopamine agonists (cabergoline) be used in acromegaly?
Some pituitary tumours co-secrete GH and prolactin
What is the GH antagonist used in acromegaly?
Pegvisomant - binds to GH receptor
What is the follow up for acromegaly?
Achieve clinically safe levels (GH <0.4ug/l post GGT)
IG1 normal
Check thyroid
Cancer surveillance (colon and tubulovillous adenoma)
CV risk (BP, lipids, glucose)
Sleep apnoea
