Hypopituitarism

Question 1

What are the hormones of the anterior pituitary?

Answer 1

Growth Hormone
Prolactin
Thyroid stimulating hormone
Luteinising hormone
Adrenocorticotrophic hormone

Question 2

What is primary gland failure?

Answer 2

The gland itself fails/ is damaged due to an autoimmune condition

Question 3

What is secondary gland failure?

Answer 3

There are no signals from the hypothalamus or anterior pituitary to the gland

Question 4

What are the expected hormone levels of TSH and T3/T4 during primary hypothyroidism?

Answer 4

eg. Autoimmune destruction of the thyroid gland - low T3/T4 and high TSH (lack of inhibition via neg. feedback)

Question 5

What are the expected hormone levels of TSH and T3/T4 during secondary hypothyroidism?

Answer 5

eg. Pituitary adenoma - low TSH as thyrotrophs are damaged and thus low T3/T4 (no TSH to stimulate its production)

Question 6

What are the expected hormone levels of ACTH and cortisol during primary hypoadrenalism?

Answer 6

eg. Destruction of the adrenal cortex - low cortisol and high ACTH (lack of inhibition)

Question 7

What are the expected hormone levels of ACTH and cortisol during secondary hypoadrenalism?

Answer 7

eg. Pituitary tumour damaging corticotrophs - low ACTH and thus low cortisol

Question 8

What are the expected hormone levels of FSH/ LH and testosterone/ oestrogen during primary hypogonadism?

Answer 8

eg. destruction of the testes (mumps) or destruction of ovaries (chemo) - testosterone/ oestrogen low and high LH/ FSH

Question 9

What are the expected hormone levels of FSH/ LH and testosterone/ oestrogen during secondary hypogonadism?

Answer 9

eg. Pituitary tumour damaging gonadotrophs- low LH/ FSH and thus low LH/ FSH

Question 10

What are two categories of causes of hypopituitarism?

Answer 10

Congenital and Acquired

Question 11

What is an example of the mechanism of congenital hypopituitarism?

Answer 11

PROP1 mutation - mutation of the transcription factor genes for the normal development of anterior pituitary - leads to deficiency in GH and at least one more hormone

Question 12

What are examples of acquired hypopituitarism?

Answer 12

Tumours
Radiation
Infection - meningitis
Peri-partum infaction (Sheehan's syndrome)
Pituitary apoplexy

Question 13

Which hormones are most sensitive to radiotherapy

Answer 13

gonadotrophins and GH

Question 14

How does low FSH/ LH present?

Answer 14

Reduced libido
Secondary amenorrhea
Erectile dysfunction
Reduced pubic hair

Question 15

How does low ACTH present?

Answer 15

Fatigue

Question 16

How does low TSH present?

Answer 16

Fatigue

Question 17

How does low Gh present?

Answer 17

reduced quality of life

Short stature in children

Question 18

How does low prolactin present?

Answer 18

Inability to breastfeed

Question 19

How is Sheehan’s syndrome caused?

Answer 19

Post-partum haemorrhage leads to hypotension. The anterior pituitary is enlarged during pregnancy due to lactotroph hyperplasia and in its enlarged state, the drop in BP leads to pituitary infarction and subsequent loss of pituitary function

Question 20

What are symptoms of Sheehan’s syndrome?

Answer 20

Lethargy
Anorexia
Weight loss
TSH/ ACTH deficiency
Failure of lactation (prolactin deficiency)
Failure to resume menses post delivery (longer than usual)
Note: posterior pituitary not usually affected

Question 21

How can Sheehan’s syndrome be treated?

Answer 21

HORMONE REPLACEMENT:

Levothyroxine for TSH deficiency (use fT4 to adjust dose)
Prednisolone/ hydrocortisone for ACTH deficiency (MUST BE TOLD SICK DAY RULES)
Oestrogen + progesterone (oral/ topical) - if fertility is required, must take FSH/ LH injections
GH injections after deficiency identified + QoL questionnaire indicated its need

Question 22

How is pituitary apoplexy caused?

Answer 22

Intra-pituitary haemorrage or infarction
Usually caused by a bleed into an existing pituitary tumour
Can be precipitated by anti-coagulants such as warfarin

Question 23

What are symptoms of pituitary apoplexy?

Answer 23

Severe sudden onset headache
Vision issues – bitemporal hemaniopia (compressed optic chiasm)
Diplopia (see two images of the same thing )/ ptosis (drooping or falling of the upper eyelid) if cavernous sinus is involved

Question 24

How can pituitary apoplexy be treated?

Answer 24

Severe: requires surgery to relieve pressure on pituitary gland/ improve vision impairment
Less severe: conservative management – hormone replacement and regular check ups
Cortisol replacement (prednisolone/ hydrocortisone) to reduce swelling and treat ACTH deficiency