L16 - Pituitary Disorders Flashcards
Pituitary disorders can be functional or non-functioning, how can non-functioning tumours lead to inadequate production of the pituitary hormones?
Physical pressure from the tumour on the tissue
What symptoms could a patient with a non-functioning pituitary adenoma present with?
Headache/visual problems due to compression of the optic chiasm - more specifically a bitemporal hemi-anopia (partial blindness in the outer half of the visual fields) and potentially ptosis due to 3rd nerve palsy/ vomiting and nausea
What would the clincical symptoms of a functional tumour relate to?
The effects of the hormone which is being under of overproduced
If a functional pituitary tumour is inhibitory what does it cause?
Hypopituitarism - this can be the result of an decrease in stimulatory hormones or an increase in inhibitory hormones from the hypothalamus - the only one would be dopamine
Apart from a pituitary adenoma what other causes are there for hypopituitarism?
Radiation therapy/inflammatory disease/head injury
What three hormones does a hypersecreting pituitary adenoma cause excess of?
Prolactin
Growth hormone
ACTH
What causes a hyperprolactinaemia (elevated serum prolactin) apart from a pituitary adenoma?
Pregnancy, suckling, stress, dopamine antagonists (anti-psychotics)
What is the first line treatment for patients with a prolactin excess?
Dopamine agonists
Which test is used for suspected forming deficiency and which for suspected hormone excess?
Deficiency - hormone stimulation test
Excess - hormone suppression test
If a tumour causes compression in a section of the right optic nerve only what will be the result on vision?
Complete blindness in left eye
Suggest some tests in a suspected functional pituitary adenoma
Test for hormone levels using suppression/stimulation tests / MRI/ visual field testing/blood test for hormone levels
Why is it important never to operate on a pituitary adenoma unless you know if it’s a prolactinoma?
Because prolactinomas can be treated with dopamine agonist rather than operatively
If peripheral prolactin levels are really low (<5000) along with lowe levels of other pituitary hormones, what kind of tumour does it indicate?
A non-functioning tumour - if this is the case a trans-sphenoidal surgery may be required
Acromegaly is the result of a GH-secreting pituitary adenoma in the adult which can be seen as large extremities and prominent forehead. What are some long term complications of acromegaly?
Hypertension Diabetes Irreversible disfigurations Premature cardiac death Increased risk of thyroid cancer/colonic tumours
What test is used to diagnose acromegaly?
Glucose tolerance test. If 1 microgram/L can’t suppress the excess hormone then it’s acromegaly
What is the treatment for acromegaly?
Trans-sphenoidal hypophysectomy, dopamine agonists, pegvisomant (GH receptor antagonist)
Cushing disease is caused by an ACTH-secreting tumour, give some symptoms
Moon face Round abdomen High BP and diabetes Osteoporosis Stretch marks on abdomen
Cushing’s syndrome is different from cushings disease in that it can be caused by other pathologies than a pituitary tumour, give some causes
Steroids, adrenal tumour
An ADH deficiency can result in diabetes insipidus meaning water isn’t reabsorbed, if this is caused by a pituitary tumour it is cranial DI if by a kidney tumour causing resistance it is a nephrogenic DI. Give the standard treatment for cranial DI
Desmopressin nasal spray and regular fluids
What is pituitary apoplexy?
A haemorrhage within a pituitary tumour
What is a classical presentation of pituitary apoplexy
Sudden headache Double vision Ptosis (cranial nerve palsy) Visual field loss Hypopituitarism - GH and gonadotropins usually affected first so very low sense of well-being, loss of secondary sexual characteristics
What would be the clinical presentation of a gonadotrophin deficiency as the result of a pituitary adenoma?
Loss of secondary sexual chaaracteristics in adults
Loss of periods in women
Gynocamastia in men
What would be the presentation of a tumour causing the following:
a) TSH deficiency
b) ACTH deficiency
a) weight gain, cold, tired, slow pulse
b) -> low cortisol - tired, low, BP, dizzy, depressed
