Pituitary problems

Question 1

Most pituitary tumours arise from the anterior / posterior pituitary gland?

Answer 1

Anterior

Question 2

Which direction do most pituitary tumours grow? and which structure can this affect?

Answer 2

Upwards

Can press on the optic chiasma

Question 3

What can result if the pituitary tumour presses on the optic chiasma?

Answer 3

Affects the visual pathway, leading to a bilateral hemianopia

Question 4

If the tumour grows laterally, what is it likely to affect?

Answer 4

Cranial nerves III, IV, VI

Question 5

Prolactinoma - definition

Answer 5

Benign tumour which causes deviation of the pituitary stalk

This results in loss of dopamine and thus hyperprolactinaemia

Question 6

Prolactinoma - if there is LOSS of dopamine, MORE / LESS prolactin will be produced?

Answer 6

Loss of dopamine, more prolactin produced

Question 7

Prolactinoma - clinical features in females

Answer 7

Early presentation
Galactorrhoea (spontaneous breast milk production) 
Menstrual irregularity
Amennorrhoea
Infertility

Question 8

Prolactinoma - clinical features in males

Answer 8

Late presentation
Lack of libido
Impotence
Headache

Question 9

Prolactinoma - investigations

Answer 9

Check prolactin blood levels
Check other pituitary function tests
MRI pituitary
Check visual fields

Question 10

Prolactinoma - management

Answer 10

Dopamine agonist (cabergoline) 
this lowers prolactin levels and causes tumour shrinkage

Question 11

Non-functioning pituitary adenoma

Answer 11

Tumour which doesn't secrete any hormones i.e.
hypothyroidism
hypopituitarism
hypoadrenalism
hypogonadism
GH deficiency

Question 12

Hypopituitarism - definition

Answer 12

Occurs when the pituitary gland is not producing all of its hormones

Question 13

Hypopituitarism - causes

Answer 13

Pituitary tumours 
Brain tumours
Granulomatous disease - TB, sarcoidosis 
Surgery/radiation 
Trauma 
Sheehan's syndrome

Question 14

Hypopituitarism - investigations

Answer 14

Baseline pituitary function tests

Stimulation test needed (as not currently producing enough hormones)

Question 15

Hypopituitarism - stimulation test findings

Answer 15

If when stimulated, hormone production increases then this is normal
If when stimulated, hormone production remains low, there is a problem

Question 16

Hypopituitarism - anterior pituitary gland

Answer 16

Hypothyroidism (no TSH)
Growth failure (no GH) 
Hypogonadism (no FSH or LH) 
No cortisol (no ACTH)
Increased prolactin (no dopamine)

Question 17

Hypopituitarism - management

Answer 17

Hormone replacement therapy (HRT)

Question 18

Hypopituitarism of the posterior pituitary land causes which condition?

Answer 18

Diabetes insipidus

Question 19

Diabetes insipidus - definition

Answer 19

Lack of ADH (vasopressin) acting on the kidneys
This results in water retention
There is water loss due to hypernatraemia (increased Na+ concentration)

Question 20

What are the two types of diabetes insipidus?

Answer 20

Cranial

Nephrogenic

Question 21

Diabetes insipidus - causes

Answer 21

Familial
Surgery
Tumour
Meningitis

Question 22

Diabetes insipidus - clinical features

Answer 22

Pee out lots of dilute urine
Thirst
Symptoms that develop suddenly after a long headache

Question 23

Diabetes insipidus - investigations

Answer 23

Water deprivation test

Measure U&E’s, measure glucose

Question 24

Diabetes insipidus - water deprivation test

Answer 24

Don’t give patient anything to drink for 8 hours and see if it is possible to concentrate their urine

• In normal patients, urine osmolality should be 2x the plasma osmolality (i.e. patient should pee out a small volume of concentrated urine)
• In Diabetes insipidus patients, still pee lots of dilute urine

Question 25

Diabetes insipidus - management

Answer 25

Demospray (nasally)

Desmopressin (Oral/injection)

Question 26

SIADH - definition

Answer 26

Syndrome of inappropriate ADH (vasopressin) release

Question 27

SIADH - causes

Answer 27

Paraneoplastic syndrome

Ectopic secretion of ADH by tumours