Hypopituitarism

Question 1

Define:

Answer 1

Deficiency in one or more of the hormones secreted by the anterior pituitary.

GH –> LH/FSH –> prolactin –>TSH –> ACTH (the order in which they are affected)

Question 2

Aetiology/Risk factors:

Answer 2

• Hypothalamus affected
• Pituitary stalk
• Pituitary
• Pituitary Masses

Question 3

Hypothalamus causes:

Answer 3

o	Kallman’s Syndrome
o	Tumour
o	Inflammation
o	Infection – meningitis, TB
o	Ischaemia 
o	Dysfunction due to anorexia, starvation or over-exercise

Question 4

Pituitary stalk causes:

Answer 4

o	Trauma – base of skull fractures
o	Surgery
o	Mass lesion – craniopharyngioma (tumour arising from Rathke’s pouch situated between the pituitary and 3rd ventricle floor)
o	Meningioma
o	Carotid artery aneurysm

Question 5

Pituitary causes:

Answer 5

o Tumour – adenoma mostly, cysts
o Irradiation
o Inflammation
o Autoimmunity
o Infiltration – haemochromatosis, amyloid, metastases, sarcoidosis
o Ischaemia – pituitary apoplexy (rapid pituitary enlargement from a bleed into a tumour may cause mass effects, CVS collapse due to mass hypopituitarism and death), DIC, Sheehan’s
o Genetic Mutations - Pit-1 and Prop-1 genes

Question 6

Pituitary mass causes:

Answer 6

o Most commonly adenomas
o Others include craniopharyngioma, meningioma, glioma, metastases
o Cysts

Question 7

Epidemiology:

Answer 7

Pituitary adenoma annual incidence: 1/100,000

Question 8

Signs and symptoms of low GH:

Answer 8

CHILDREN: short stature

ADULTS: low mood, fatigue, reduced exercise capacity and muscle strength, increased abdominal fat mass, dry wrinkly skin, reduced balance and strength, osteoporosis, a therosclerosis, low CO

Question 9

Signs and symptoms of low LH/FSH:

Answer 9

• 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

Question 10

Signs and symptoms of low ACTH:

Answer 10

Signs/symptoms of adrenal insufficiency

Question 11

Signs and symptoms of low TSH:

Answer 11

signs/symptoms of hypothyroidism

Question 12

Signs and symptoms of low prolactin:

Answer 12

Lack of lactation

Question 13

Signs and symptoms of pituitary apoplexy:

Answer 13

o Headache
o Visual loss
o Cranial nerve palsies

Question 14

Investigations:

Answer 14

•	Pituitary Function Tests
o	Basal Tests
•	9 am cortisol
•	LH and FSH levels 
•	Testosterone levels 
•	Oestrogen levels 
•	IGF-1 levels 
•	Prolactin levels – may be high due to loss of hypothalamic dopamine that normally inhibits its release
•	Free T4 and TSH levels 
o	Dynamic Tests (rarely performed)
•	Insulin-induced hypoglycaemic (should cause a rise in GH and cortisol) 
o	Short synacthen test (for adrenal insufficiency)
o	MRI/CT of brain 
o	Visual field testing

Question 15

Management:

Answer 15

•	Hormone Replacement
o	Hydrocortisone 
o	Levothyroxine
o	Sex hormones 
•	Testosterone in males 
•	Oestrogen with/without progesterone in females 
•	Growth hormone 
•	Desmopressin (if central diabetes insipidus as a result of panhypopituitarism)

Question 16

Complications:

Answer 16

•	Addisonian crisis 
•	Hypoglycaemia 
•	Myxoedema coma 
•	Infertility
•	Osteroporosis 
•	Dwarfism (children) 
•	Complications of pituitary mass:
o	Optic chiasm compression (leading to bitemporal hemianopia) 
o	Hydrocephalus 
o	Temporal lobe epilepsy

Question 17

Prognosis:

Answer 17

• GOOD prognosis with lifelong treatment