L16 - Pituitary Disorders

Question 1

Pituitary disorders can be functional or non-functioning, how can non-functioning tumours lead to inadequate production of the pituitary hormones?

Answer 1

Physical pressure from the tumour on the tissue

Question 2

What symptoms could a patient with a non-functioning pituitary adenoma present with?

Answer 2

Headache/visual problems due to compression of the optic chiasm - more specifically a bitemporal hemi-anopia (partial blindness in the outer half of the visual fields) and potentially ptosis due to 3rd nerve palsy/ vomiting and nausea

Question 3

What would the clincical symptoms of a functional tumour relate to?

Answer 3

The effects of the hormone which is being under of overproduced

Question 4

If a functional pituitary tumour is inhibitory what does it cause?

Answer 4

Hypopituitarism - this can be the result of an decrease in stimulatory hormones or an increase in inhibitory hormones from the hypothalamus - the only one would be dopamine

Question 5

Apart from a pituitary adenoma what other causes are there for hypopituitarism?

Answer 5

Radiation therapy/inflammatory disease/head injury

Question 6

What three hormones does a hypersecreting pituitary adenoma cause excess of?

Answer 6

Prolactin
Growth hormone
ACTH

Question 7

What causes a hyperprolactinaemia (elevated serum prolactin) apart from a pituitary adenoma?

Answer 7

Pregnancy, suckling, stress, dopamine antagonists (anti-psychotics)

Question 8

What is the first line treatment for patients with a prolactin excess?

Answer 8

Dopamine agonists

Question 9

Which test is used for suspected forming deficiency and which for suspected hormone excess?

Answer 9

Deficiency - hormone stimulation test

Excess - hormone suppression test

Question 10

If a tumour causes compression in a section of the right optic nerve only what will be the result on vision?

Answer 10

Complete blindness in left eye

Question 11

Suggest some tests in a suspected functional pituitary adenoma

Answer 11

Test for hormone levels using suppression/stimulation tests / MRI/ visual field testing/blood test for hormone levels

Question 12

Why is it important never to operate on a pituitary adenoma unless you know if it’s a prolactinoma?

Answer 12

Because prolactinomas can be treated with dopamine agonist rather than operatively

Question 13

If peripheral prolactin levels are really low (<5000) along with lowe levels of other pituitary hormones, what kind of tumour does it indicate?

Answer 13

A non-functioning tumour - if this is the case a trans-sphenoidal surgery may be required

Question 14

Acromegaly is the result of a GH-secreting pituitary adenoma in the adult which can be seen as large extremities and prominent forehead. What are some long term complications of acromegaly?

Answer 14

Hypertension 
Diabetes
Irreversible disfigurations 
Premature cardiac death 
Increased risk of thyroid cancer/colonic tumours

Question 15

What test is used to diagnose acromegaly?

Answer 15

Glucose tolerance test. If 1 microgram/L can’t suppress the excess hormone then it’s acromegaly

Question 16

What is the treatment for acromegaly?

Answer 16

Trans-sphenoidal hypophysectomy, dopamine agonists, pegvisomant (GH receptor antagonist)

Question 17

Cushing disease is caused by an ACTH-secreting tumour, give some symptoms

Answer 17

Moon face
Round abdomen
High BP and diabetes
Osteoporosis 
Stretch marks on abdomen

Question 18

Cushing’s syndrome is different from cushings disease in that it can be caused by other pathologies than a pituitary tumour, give some causes

Answer 18

Steroids, adrenal tumour

Question 19

An ADH deficiency can result in diabetes insipidus meaning water isn’t reabsorbed, if this is caused by a pituitary tumour it is cranial DI if by a kidney tumour causing resistance it is a nephrogenic DI. Give the standard treatment for cranial DI

Answer 19

Desmopressin nasal spray and regular fluids

Question 20

What is pituitary apoplexy?

Answer 20

A haemorrhage within a pituitary tumour

Question 21

What is a classical presentation of pituitary apoplexy

Answer 21

Sudden headache
Double vision
Ptosis (cranial nerve palsy)
Visual field loss 
Hypopituitarism - GH and gonadotropins usually affected first so very low sense of well-being, loss of secondary sexual characteristics

Question 22

What would be the clinical presentation of a gonadotrophin deficiency as the result of a pituitary adenoma?

Answer 22

Loss of secondary sexual chaaracteristics in adults
Loss of periods in women
Gynocamastia in men

Question 23

What would be the presentation of a tumour causing the following:

a) TSH deficiency
b) ACTH deficiency

Answer 23

a) weight gain, cold, tired, slow pulse

b) -> low cortisol - tired, low, BP, dizzy, depressed