pituitary physiology & tumours

Question 1

what structures does a large non functioning pituitary adenoma compress?

Answer 1

optic chiasma
can compress other structures e.g. cranial nerves 3, 4 & 6

Question 2

what is the management of pituitary non functioning adenoma that is compressing the optic chiasma?

Answer 2

transphenoidal surgery
replace hormones

Question 3

what are causes of raised prolactin?

Answer 3

physiological - breastfeeding, pregnancy, stress, sleep

pharmacological- dopamine antagonists (e.g. metclopramide), antipsychotics (e.g. phenothiazines)

Question 4

what are some pathological causes of raised prolactin?

Answer 4

hypothyroidism, stalk lesions, prolactinoma

Question 5

what are the female symptoms of raised prolactin?

Answer 5

EARLY presentation
Galactorrhoea (milky nipple discharge)
Menstrual irregularity
Ammenorrhoea
Infertility

Question 6

what are the male symptoms of raised prolactin?

Answer 6

LATE Presentation
Impotence
Visual field abnormal
Anterior pituitary malfunction

Question 7

what investigations do you do fro prolactinoma?

Answer 7

serum prolactin concentration
MRI pituitary (is it too big?)
visual fields
pituitary function test to see if other hormones are affected

Question 8

what is the most commonly used medication for for prolactinona?

Answer 8

dopamine agonists (cabergoline, bromocriptine, quinagolide)

Question 9

what are the side effects of dopamine agonists?

Answer 9

nausea/vomiting
low mood
obsessive compulsive behaviour

Question 10

what are the symptoms and effects of acromegaly- GH excess

Answer 10

thickened soft tissues - large hands, jaw
very tall
snoring / sleep apnoea
hypertension
headaches (vascular)
diabetes mellitus
local pituitary effects
early cv death
colonic polyps and colon cancer

Question 11

what are the treatments for acromegaly?

Answer 11

pituitary surgery (90% cure if smaller than 1cm, 50% if bigger)
or radiotherapy alone

Question 12

what drugs are used for acromegaly?

Answer 12

somatostatin analogues (sandostatin LAR or lanreotide)- reduces GH and shrinks tumour, relieves headache

Question 13

what are the side effects of somatostatin analogues?

Answer 13

local stinging
short term flatulence, diarrhoea, abdo pain
long term- gallstones

Question 14

what other types of drugs can be used for acromegaly

Answer 14

high dose dopamine agonists, GH antagonists

Question 15

what other features should be managed in acromegaly?

Answer 15

cancer surveillance- colon and tubulo-villous adenoma
cv risk factors
sleep apnoea

Question 16

what causes cushing’s syndrome?

Answer 16

excess cortisol
can result from pituitary tumours, taking long term corticosteroids, adrenal adenoma, ectopic ACTH production and alcohol and depression

Question 17

what are the symptoms of cushing’s synrdome?

Answer 17

protein loss- myopathy, wasting, thin skin, osteoporosis
altered carbohydrate & lipid metabolism- obesity & diabetes mellitus
psychosis, depression
acne, hirsuitism, oglio/ameorrhoea

Question 18

what are the diagnostic tests for cushing’s?

Answer 18

overnight 1mg dexamethasone suppression test - cortisol >130 = definitely cushing’s
urine free cortisol (24hr urine collection)
diurnal cortisol variation (8am compared to midnight) - loss of variation in cortisol levels between times of day suggests cushing’s

Question 19

what is the name for cushing’s syndrome caused by a pituitary tumour?

Answer 19

cushing’s disease (all other types are cushing’s syndrome)

Question 20

what is the treatment for cushing’s disease?

Answer 20

Hypophysectomy (Transsphenoidal route) and
external radiotherapy if recurs
Bilateral adrenalectomy

Question 21

what is the treatment for adrenal cushing’s syndrome?

Answer 21

adrenalectomy

Question 22

what is the treatment for ectopic cushing’s syndrome?

Answer 22

remove source or bilateral adrenalectomy

Question 23

what are the drug treatment options for cushing’s?

Answer 23

not ideal-
metyrapone if other treatments fail or while waiting for radiotherapy to work
ketoconazole (but it is hepatotoxic)
pasireotide LAR (somatostatin analogue)

Question 24

what are the main causes of hypopituitarism?

Answer 24

pituitary tumours
other local brain tumours
iatrogenic surgery

Question 25

what are the symptoms of anterior hypopituitarism?

Answer 25

Menstrual irregularities
Infertility, impotence
Gynaecomastia
Abdominal obesity
Loss of facial hair
Loss of axillary and pubic hair
Dry skin and hair
Hypothyroid faces
growth retardation (children)

Question 26

what is the treatment for hypopituitarism?

Answer 26

hormone rpelacement-
thyroxine, hydrocortisone, ADH, GH, sex steroids

Question 27

what are the risks of testosterone replacement?

Answer 27

polycythaemia (high conc of rbcs) - risk of Mi and stroke
prostate enlargement
hepatitis - only in oral tablets

Question 28

what are the benefits of GH replacement in adults?

Answer 28

Improves well being and Quality of life
Decreases abdominal fat
Increases muscle mass, strength, exercise capacity and stamina
Improves cardiac function
Decreases cholesterol and increases LDL
Increases bone density
Given by daily SC injection

Question 29

what are the causes of cranial diabetes insipidus?

Answer 29

50% idiopathic
trauma, tumour, rarely familial

Question 30

how do you diagnose cranial diabetes insipidus?

Answer 30

water deprivation test- NBM for 8-12 hours
then do stiumlation test and if it improves it is cranial DI

Question 31

what is the treatment of diabetes insipidus?

Answer 31

desmospray, desmopressin tablets or injection