Pituitary Tumours

Question 1

what are the sizes of pituitary tumours

Answer 1

> 1cm macroadenoma

=/<1cm microadenoma

Question 2

what happens when a non functioning pituitary adenoma gets ‘too big’

Answer 2

compression on optic chiasma (if grows upwards)

compression on other structures (cranial nerve- 6th most likely to be affected) (lateral growth)

Question 3

what happens when a non functioning pituitary adenoma gets ‘too little’

Answer 3

hypoadrenalism
hypothyroidism
hypogonadism (lack of periods, erectile dysfunction)
diabetes insipidus (posterior pituitary- ADH)
GH deficiency

Question 4

what happens if the 6th cranial nerve is compressed

Answer 4

nerve allows you to look laterally- if compressed eye will squint inwards

Question 5

what is bitemporal hemanopia

Answer 5

loss of temporal fields of vision

Question 6

what is monomous hemianopia

Answer 6

vision defect all on one side (unlike bitemporal as on both sides)

Question 7

what might cause prolactin too rise excessively

Answer 7

lack of dopamine from the hypthalamus

Question 8

what are the physiological causes of raised prolactin

Answer 8

breast feeding
pregnancy
stress
sleep

Question 9

what drugs can increase prolactin

Answer 9

dopamine antagonists (metoclopramide)
antipsychotics, antidepressants, estrogens, cocaine

Question 10

what should raised prolactin and loss of periods make you think of

Answer 10

pregnancy

Question 11

what are the pathological causes of raised prolactin

Answer 11

hypothyroidism
stalk lesions (iatrogenic, road accident)
prolactinoma

Question 12

what are the female clinical signs and symptoms of a prolactinoma

Answer 12

early presentation 
galactorrhoea (lactation)
menstrual irregularity 
ammenorrhoea 
infertility

Question 13

what are the male clinical signs and symptoms of prolactinomas

Answer 13

late presentation
impotence 
visual field abnormality 
heachache (when very big, LATE presentation) 
anterior pituitary malfunction

Question 14

what are the investigations into prolactinoma

Answer 14

serum prolactin concentration (should be raised) 
MRI pituitary (micro/macroprolactinoma, pituitary stalk, optic chiasma)
visual fields 
pituitary function tests (other hormones affected)

Question 15

what is the treatment for a prolactinoma

Answer 15

dopamine agonists- cabergoline

surgery not right treatment

Question 16

what are the side effects of dopamine agonists

Answer 16

nausea/ vomiting
low mood
fibrosis (rare)

Question 17

what is important to warm women of when starting a dopamine agonists

Answer 17

common to get pregnant very shortly after starting them - menstruation regained

Question 18

what causes acromegaly

Answer 18

GH excess due to pituitary adenoma

Question 19

what are the signs of acromegaly

Answer 19

giant (before epiphyseal fusion)
thickened soft tissues (skin, large jaw, sweaty, large hands)
snoring/ sleep apnoea (thickened nasopharynx)
hypertension (heart), cardiac failure
headaches (vascular)
diabetes mellitus (stress hormone so will increase BG)
local pituitary effects (visual fields, hypopituitarism)
early CV death
colonic polyps and colon cancer

Question 20

what is IGF 1

Answer 20

molecule whos production is stimulated by GH, how GH has its effect on tissues

Question 21

how do you diagnose acromegaly

Answer 21

IGF1
glucose tolerance test (should make GH to less than 0.4 micro grams, if not/ or if paradoxical rise then acromegaly

visual field, CT or MRI pituitary scan, pituitary function tests

Question 22

what is the treatment for acromegaly

Answer 22

1st line- pituitary surgery (transphenoidal route, or from above via craiotomy)
external radiotherapy to pituitary fossa
then retest GTT
if not improved:
drugs, radiotherapy, repeat surgery if curable

Question 23

growing round what structure makes a macroadenoma hard to surgically remove

Answer 23

the carotid artery

Question 24

what drugs can be used to treat acromegaly

Answer 24

1. somatostatin analogues
   (sanostatin LAR/ lanreotide)

reduces GH in most patients
can cause tumour shrinkage or be used pre op to relive headaches

2. dopamine agonists
   (cabergoline, workes in 10-15% of patients, better id co secreting prolactin)
3. GH antagonists (pegvisomant- block GH activity, 85% response rate, tumour size doesnt decrease, IGF 1 conc decreases)- last line therapy

Question 25

what are the side effects of somatostatin analogues

Answer 25

local stinging 
short term:
-flatulence 
-diarrhoea 
-abdo pains

long term
-gallstones (stops gall bladder contraction)

Question 26

what should be included in an acromegaly follow up

Answer 26

safe GH and IGF 1 levels 
check pituitary hormones 
cancer surveillance: colon and tubulo-villous adenoma 
CV risk factors (BP, lipids, glucose) 
sleep apnoea

Question 27

is surgery the first line of treatment for acromegaly

Answer 27

yes

Question 28

what is the 1st line treatment for prolactinoma

Answer 28

dopamine agonists

Question 29

what causes an acromegalic headache

Answer 29

vascular