Hypopituitarism Flashcards
Define hypopituitarism?
Deficiency in one or more of the hormones secreted by the anterior pituitary.
Panhypopituitarism is deficiency of ALL pituitary hormones.
what are the causes of hypopituitarism?
Pituitary Masses
- Most commonly adenomas
- Others include craniopharyngioma, meningioma, glioma, metastases
- Cysts
Pituitary Trauma - radiation, surgery, base of skull fractures, empty sella turcica
Hypothalamic Dysfunction - due to anorexia, starvation, over-exercise
Infiltrative Diseases - sarcoidosis, haemochromatosis, Langerhans’ cell histiocytosis, tuberculosis
Vascular - pituitary apoplexy, Sheehan’s syndrome
- Pituitary apoplexy is the sudden spontaneous development of a haemorrhage into or infarction of a pre-existing adenoma.
- Sheehan syndrome is infarction of the pituitary after substantial blood loss with hypotension during childbirth.
Infection - meningitis, encephalitis
Genetic Mutations - Pit-1 and Prop-1 genes
what is pituitary apoplexy?
sudden spontaneous development of haemorrhage into or inarction of pre-existing adenoma
what is sheehan’s syndrome?
is infarction of the pituitary after substantial blood loss with hypotension during childbirth.
summarise the epidemiology of hypopituitarism?
Pituitary adenoma annual incidence: 1/100,000
what are the symptoms of pituitary apoplexy?
headache
visual loss
cranial nerve palsies
what are the signs and signs of hypopituitarism?
GH
- CHILDREN: short stature, failure to thrive
- ADULTS: low mood, fatigue, reduced exercise capacity and muscle strength, increased abdominal fat mass
LH or FSH
- Delayed puberty
- FEMALES: loss of secondary sexual hair, breast atrophy, menstrual irregularities, dyspareunia, decreased libido, infertility
- MALES: loss of secondary sexual hair, gynaecomastia, small and soft testes, decreased libido, impotence
ACTH- signs/symptoms of adrenal insufficiency e.g. hypoglycaemia, hypotension, N+V, fatigue, weakness, dizziness
TSH - signs/symptoms of hypothyroidism e.g. cold intolerance, weight gain, constipation, dry skin
Prolactin - absence of lactation (not usually noticed clinically)
what are the appropriate investigation for hypopituitarism?
Bloods
- Sodium – low in ACTH and TSH def vs high in DI
- Serum and urine osmorality- low urine omsolarity and high serum osmolarity
Basal Tests
- 9 am cortisol and ACTH- low
- LH and FSH levels- low
- Testosterone levels- low
- Oestrogen levels- low
- IGF-1 levels- low in GH deficiency
- Prolactin levels
- Free T4 and TSH levels- low T4 and T3 and low/ normal TSH
Dynamic Tests (rarely performed)
- Insulin-induced hypoglycaemic (should cause a rise in GH and cortisol)
- Short synacthen test (for adrenal insufficiency)
- Water deprivation and desmopressin response test (for DI)
MRI- lesion in sellar or parasellar regions
CT of brain- calcification if craniopharyngioma present
Visual field testing
Outline a management plan for hypopituitarism?
Hydrocortisone – IV given first line with pit apoplexy then norm oral dose
Levothyroxine
Sex hormones
- Testosterone in males
- Oestrogen with/without progesterone in females
- Women and men with secondary hypogonadism who desire fertility are given gonadotrophins
Growth hormone – somatropin
Desmopressin (if central diabetes insipidus as a result of panhypopituitarism)
what are the possible complications of hypopituitarism?
Addisonian crisis
Hypoglycaemia
Myxoedema coma
Infertility
Osteroporosis
Dwarfism (children)
Complications of pituitary mass:
- Optic chiasm compression (leading to bitemporal hemianopia)
- Hydrocephalus
- Temporal lobe epilepsy
state 3 complications of a pituitary mass?
Optic chiasm compression (leading to bitemporal hemianopia)
Hydrocephalus
Temporal lobe epilepsy
summarise the prognosis of hypopituitarism?
GOOD prognosis with lifelong treatment
