Pituitary disorders Flashcards
What are the usual clinical presentation of pituitary tumours?
- Visual loss = pressure on optic chiasm
- Headache = lateral growth of the tumour
What are biochemical assessments of pituitary disease?
- Thyroid axis = TSH
- Gonadal axis = LH + FSH
- Prolactin axis = Serum prolactin
What are the dynamic assessments of HPA and GH axes?
Stimulation test = suspected hormone deficiency
Suppression test = suspected hormone excess
Adrenal axis
- Deficiency = stimulate adrenals by ACTH
- Excess = suppress ACTH with steroids
GH axis
- Deficiency = response to hypoglycamic stress
- Excess = suppress GH axis with glucose load
What is prolactinoma?
Prolactin-secreting pituitary tumour
What are the symptoms of hyperprolactinaemia in women?
- Menstrual disturbance
- Fertility problems
- Galactorrhea
What are the symptoms of hyperprolactinaemia in men?
-Visual loss
-Lactation
-Erectile dysfunction
-Infertility
(usually present later than females)
What is prolactin disinhibition and what is its importance?
- Blocking of the stalk as prolactin is under tonic inhibition by dopamine
- Prolactinomas are treated medically while non-functioning pituitary tumours are treated surgically
How are prolactinomas treated?
- Dopamine agonists
- Bromocriptine or Cabergoline (reduces prolactin)
What is non-functioning pituitary adenoma?
Pituitary tumour that leads to no secretion of biologically active hormones
What are the clinical features of NFPA?
- Low testosterone
- Growth failure in children
- Menstrual cycle loss
- Infertility
- Loss of sex drive
Treatment for NFPA?
Surgery
What is acromegaly?
GH-secreting pituitary tumour that leads to large extremities (large hands and feet)
What are long term complications of acromegaly if untreated?
- Premature cardiovascular death
- Disfiguring body changes
- Hypertension
- Diabetes
What is the treatment for acromegaly?
- Surgical removal of tumour
- Dopamine agonist (reduce GH secretion)
- Somatostatin analogues (reduce GH secretion)
- Block GH receptor (e.g. pegvisomant)
- Radiotherapy
What is cushing’s disease
ACTH-secreting tumour
What are the clinical changes in appearance in cushing’s disease?
- Round pink face
- Round abdomen
- Thin skin (easy bruising)
- Red stretch marks on abdomen
What is the treatment for cushing’s disease?
- Surgery
- Radiotherapy
- Medication to reduce effect of cortisol (e.g. ketoconazole, mitotane)
What is the difference between Cushing’s disease and Cushing’s syndrome?
Cushing’s disease = due to tumour
Cushing’s syndrome = may be due to other pathologies (e.g. ectopic ACTH, steroid medication)
What is Diabetes insipidus?
Large quantities of pale (insipid) urine
How does Diabetes insipidus present?
-extreme thirst (polydipsia)
What is the difference between cranial DI and nephrogenic DI?
- Cranial DI is vasopressin deficiency pituitary disease
- Nephrogenic DI is vasopressin resistance kidney disease
What are the consequences of untreated DI?
- Severe dehydration
- Hypernatraemia
- Reduced consciousness
- Coma
- Death
What is the treatment for cranial DI?
Synthetic vasopressin (Desmopressin)
What is pituitary apoplexy?
A sudden vascular event in pituitary tumour (stroke) -> haemorrhage and/or infarction
