ENDOCRINOLOGY - HYPOPITUITARISM

Question 1

When do symptoms of Hypopituitarism appear?

Answer 1

When >75% of anterior pituitary is non functional

Question 2

Whats the sequence of loss of hormones from Hypopituitarism?

Answer 2

Go LOok For The Adenoma
GH
LH
FSH
TSH
ACTH

Question 3

What is panhypopituitarism?

Answer 3

When all pituitary hormones are low

Question 4

What symptoms does hyposecretion of FSH and LH cause?

Answer 4

Oligomenorrhoea
Amenorrhoea
Infertility
Loss of pubic hair - men
Reduction of muscle mass - men
Diminished libido

Question 5

What symptoms does hyposecretion of ACTH cause?

Answer 5

Weight loss
Delayed puberty
Hypoglycaemia
Hyponatraemia

weakness, nausea, vomiting, and low blood pressure (hypotension)

Question 6

What symptoms does hyposecretion of GH cause?

Answer 6

Failure of growth in children
Delayed puberty
Lean body mass
Low bone density in adults

Question 7

What symptoms does hyposecretion of TSH cause?

Answer 7

Weight gain
Constipation
Hair loss
Depression
Hypotension
(Signs of hypothyroidism)

Question 8

What can cause Hypopituitarism?

Answer 8

Pituitary adenoma
Craniopharyngioma in children
Empty sella syndrome
Pituitary apoplexy
Sheehan syndrome
Hypothalamic tumours
Trauma
Infiltration - haemachromatosis and sarcoidosis
Iatrogenic e.g. radiotherapy

Question 9

How is Hypopituitarism diagnosed?

Answer 9

Serum thyroid levels and measure serum cortisol in am
Stimulation tests can be done if necessary
(GH and ACTH levels vary throughout the day)
MRI to look for tumours and haemorrhage

Question 10

How is Hypopituitarism treated?

Answer 10

Hormone replacement e.g. hydrocortisone in ACTH deficiency or levothyroxine in TSH deficiency, testosterone or oestrogen-progestin in FSH and LH deficiencies
Surgical excision of tumour

Question 11

What is pituitary apoplexy?

Answer 11

Sudden enlargement of a pituitary tumour (usually non-functioning macroadenoma) secondary to haemorrhage or infarction.

Question 12

Whats the blood supply to the pituitary gland?

Answer 12

Superior hypophyses artery and inferior hypophyses artery

Question 13

What can cause a pituitary apoplexy?

Answer 13

Haemorrhage - most common
Infarction

Question 14

What causes haemorrhage in pituitary apoplexy?

Answer 14

Pituitary adenoma
Brain surgery
Trauma to head

Question 15

How can a pituitary adenoma cause a haemorrhage leading to pituitary apoplexy?

Answer 15

Large tumours demand more blood and increased blood flow means increased pressure in the vessels, eventually causing them to rupture. The blood collects in the interstitium, making the pituitary gland swell up. An enlarged pituitary gland compresses sournding structures e.g. meninges = pain, optic nerves = bitemporal hemianopia. This pool of blood can put pressure on nearby blood vessels, pinching them shut and causing ischaemia.

Question 16

Whats the most common reason for infarction of pituitary causing pituitary apoplexy?

Answer 16

Sheehans syndrome

Question 17

What are the symptoms of pituitary apoplexy?

Answer 17

Sudden onset severe headache, vomiting, neck stiffness, bitemporal hemianopia, extraocular nerve palsies

Overtime pituitary dysfunction symptoms will occur:
Low ACTH and cortisol - hypoglycaemia, hypotension, loss of consciousness (medical emergency)
TSH - weight gain, cold intolerance
GnRH - menstrual problems, low libido, infertility
Prolactin - agalactorrhoea
GH - fatigue and loss of muscle mass

Question 18

How is pituitary apoplexy diagnosed?

Answer 18

MRI shows enlarged pituitary with hyperintense blood filled centre
Blood tests can look for panhypopituitarism also

Question 19

How id pituitary apoplexy treated>

Answer 19

Emergency replacement of glucocorticoids
Replacement of deficient hormones for rest of life
Transphenoidal surgical resection of pituitary tumours

Question 20

What is Sheehan syndrome?

Answer 20

Postpartum pituitary gland necrosis

Question 21

Outline the pathology of Sheehan syndrome?

Answer 21

The pituitary increases in size during gestation due to metabolic activity of lactotrophs increasing.However, the blood supply does not so the pituitary is vulnerable to perfusion decrease.
Postpartum haemorrhage leads to ischaemia of pituitary gland so it progressively shrinks, scars and stops producing enough of some hormones. In severe cases, destruction and scarring can lead to an empty sella turcica. This results in Hypopituitarism

Question 22

What are the main symptoms of Sheehan syndrome?

Answer 22

Classic early symptom is agalactorrhoea
Amenorrhoea, hypothyroidism, adrenal gland insufficiency symptoms, low GH symptoms

Question 23

How is Sheehan syndrome diagnosed?

Answer 23

measuring pituitary hormone levels
MRI show ring enhancement/halo around partially or completely empty sella turcica - aka the pituitary ring sign

Question 24

How is Sheehan syndrome treated?

Answer 24

replace deficient hormones for life (note: glucocorticoid replacement will be needed urgently if adrenal insufficiency)

Question 25

What can cause hypoprolactinemia?

Answer 25

Sheehan syndrome (most common)
Dopamine agonist use
Tumour in pituitary or hypothalamus which puts pressure on nearby lactotroph cells and interfere with their ability to produce prolactin

Question 26

What are symptoms of hypoprolactinemia?

Answer 26

Only causes symptoms in breastfeeding women who can get agalactorrhoea

Question 27

How is hypoprolactinemia diagnosed?

Answer 27

Decreased serum prolactin levels
MRI to see tumour

Question 28

What is hypophysitis?

Answer 28

Inflammation of pituitary gland or stalk that typically results in varying degrees of pituitary gland failure

Question 29

What are the side effects of testosterone in men?

Answer 29

Gynaecomastia (as androgens get turned into oestrogen)
Worsens sleep apnoea
Worsens testicular cancer
Stimulates BPH