Pituitary

Question 1

T or F :
Pituitary failure causes hypotension

Answer 1

FALSE

Question 2

In which endocrine organ failure is blood pressure low? Which hormone is low causing this?

Answer 2

Addison’s disease (adrenal)

Low Aldosterone (+ Cortisol)

Question 3

Which hormones are low in pituitary failure?

Answer 3

Growth Hormone
Prolactin
TSH
LH
FSH
ACTH

Question 4

Which hypothalamic hormone is inhibitory, and on the production of which anterior pituitary hormone?

Answer 4

Dopamine is inhibitory on the production of Prolactin

Question 5

What does thyrotropin releasing hormone stimulate in the anterior pituitary?

Answer 5

TSH
Prolactin

Question 6

In a patient presenting with galactorrhea/ amenorrhoea and a macroadenoma (>1cm) what complication should you examine for?

Answer 6

Bitemporal hemianopia

(Macroadenoma presses on optic chiasm)

Question 7

30F
Galactorrhea
Amenhorroea
2cm macroadenoma on CT
Prolactin: 30,000
What is the diagnosis? What further investigation is necessary?

Answer 7

Prolactinoma

(normal <600)

Pituitary function testing

Question 8

Why is pituitary function testing performed when a pituitary tumour is detected?

Answer 8

Tumour will press on other cells- potentially squeeze them out of existing
To ensure pituitary gland responds adequately to metabolic stress (ACTH + GH)
To ensure gonadotropins + thyrotrophs are functional

Question 9

What are the elements of a combined pituitary function test? (CPFT)

Answer 9

LHRH to increase LH + FSH
TRH to increase TSH + prolactin
Stress to test ACTH + GH

Question 10

What kind of stress is used in a CPFT?

Answer 10

Insulin induced hypoglycaemic stress
Increases CRH + thus ACTH
Increases GHRH + thus GH

Question 11

What conditions must be checked for prior to a hypoglycaemic stress test?

Answer 11

Cardiac RFs/ Angina/ Abnormal ECG (may precipitate MI)
Epilepsy (may precipitate fit)

Question 12

How may a patient react behaviourally to a hypoglycaemic stress test?

Answer 12

Low glucose: Sympathetic activation- sweaty, palpitations
V low glucose <1.5: Neuroglycopenia, aggression

Question 13

What is considered adequate stress in hypoglycaemia in CPFT?

Answer 13

<2.2mM

Question 14

What action must be taken if severe hypoglycaemia or unconsciousness occurs in a CPFT?

Answer 14

Rescue patient with 50ml of 20% Dextrose
Need good IV access prior as pt may become aggressive

Question 15

Describe methodology of a CPFT

Answer 15

Fast patient overnight
Ensure good IV access
Weigh patient + calculate dose of insulin required: 0.15 units/ kg
Insulin + 200mcg TRH + 100mcg LHRH IV bolus

Question 16

How frequently should measurements be recorded in a CPFT?

Answer 16

Glucose, Cortisol, GH, LH, FSH, TSH + Prolactin every 30m up to 60m
+ basal thyroxine
Glucose, Cortisol + GH up to 120m

Question 17

Describe these results seen in a patient with a prolactinoma

Answer 17

Glucose drops- significant hypo
No GH produced
No rise in Cortisol
No rise in LH, FSH or TSH
Prolactin remains sky high

Question 18

In a patient who has failed to respond to a CPFT, which treatment is needed urgently?

Answer 18

Hydrocortisone replacement

Thyroxine, GH, HRT but not urgent
(don’t need fludrocortisone, already have aldosterone as Adrenals healthy)

Question 19

In addition to hormone replacement, what drug should be prescribed to a patient with a prolactinoma?

Answer 19

Cabergoline or Bromocriptine
Dopamine agonists to reduce prolactin

Question 20

27F with a 2cm pituitary adenoma and bitemporal hemianopia

What occurs in the CPFT?
What is the diagnosis? Why is the prolactin high?

Answer 20

Glucose falls
GH remains the same

Non-functioning pituitary adenoma
Press on stalk causing pituitary failure
Prevent dopamine reaching lactotrophs causing secondary hyperprolactinaemia

Question 21

What treatment is NOT needed in a 27F with a non functioning pituitary adenoma?
A. Fludrocortisone replacement
B. Hydrocortisone replacement
C. Thyroxine replacement
D. Oestrogen replacement
E. GH replacement

Answer 21

A. Fludrocortisone replacement

Question 22

In a patient with a non functioning pituitary adenoma, what treatment may be offered on top of hormone replacement? Why?

Answer 22

Cabergoline if they want to get pregnant

Question 23

28F with a 2cm pituitary adenoma and a bitemporal hemianopia.
Describe the abnormalities.
What is the diagnosis?

Answer 23

Glucose falls
GH increases
Baseline cortisol is low
Thyroxine is low because tumour has caused hypothyroidism
High prolactin suggests tumour
Pituitary gland failure except GH

Acromegaly

Question 24

When suspecting acromegaly what dynamic test is needed?
A. Low dose dexamethasone suppression test
B. High dose dexamethasone suppression test
C. Synacthen test
D. Glucose tolerance test
E. TRH stimulation test

Answer 24

Glucose tolerance test

Question 25

Other than a glucose tolerance test, what other test can confirm diagnosis of Acromegaly?

Answer 25

IGF1

Question 26

What is the best treatment for acromegaly ?
A. Pituitary surgery
B. Pituitary radiotherapy
C. Cabergoline
D. Octreotide
E. All of the above

Answer 26

E. All of the above

Surgery preferential if operable size + location

Question 27

What is seen here?

Answer 27

Adrenal glands of different sizes