Pituitary disease/tumours

Question 1

Where is the optic chiasm in relation to the pituitary gland?

Answer 1

optic chiasm is above pituitary gland

Question 2

How do pituitary masses cause chiasmal visual problems?

Answer 2

suprasellar pituitary masses grow up and compress the optic chiasm
causes bitemporal hemianopia

Question 3

What does the pituitary gland do?

Answer 3

master gland in charge of other glands:
- thyroid
- adrenals
- ovaries/testes

has effect on breast milk production, growth and fluid balance

Question 4

ACTH function

Answer 4

stimulates production/secretion of glucocorticoids from adrenal cortex

Question 5

TSH function

Answer 5

stimulates production/secretion of thyroid hormones

Question 6

What hormones does the anterior pituitary gland secrete?

Answer 6

ACTH
TSH
LH/FSH
PRL (prolactin)
GH

Question 7

What hormone stimulates the release of ACTH?

Answer 7

CRH (corticotrophin releasing hormone)

Question 8

What hormone stimulates the release of TSH?

Answer 8

TRH (thyrotrophin releasing hormone)

Question 9

What hormone stimulates the release of LH/FSH?

Answer 9

GnRH (gonadotrophin releasing hormone)

Question 10

What hormone stimulates the release of GH?

Answer 10

GHRH (growth hormone releasing hormone)

Question 11

What inhibits growth hormone?

Answer 11

somatostatin

Question 12

What inhibits prolactin?

Answer 12

dopamine

Question 13

Hypopituitarism causes

Answer 13

Infective
Vascular - pituitary apoplexy, Sheehan’s
Immunological - antibodies
Neoplastic
Traumatic - skull fracture
Infiltration
Radiation damage
Empty sella syndrome
Functional - anorexia nervosa, starvation, emotional deprivation

Question 14

What is gigantism?

Answer 14

excessive growth hormone before epiphyseal fusion (children)

Question 15

What is acromegaly?

Answer 15

excessive growth hormone after epiphyseal fusion - will not get very tall as bones already fused

Question 16

What are the new names for diabetes insipidus (cranial + nephrogenic)?

Answer 16

AVP deficiency = cranial DI
AVP resistance = nephrogenic DI

Question 17

What is given when prolactin levels are high? (eg. in a prolactinoma)

Answer 17

dopamine agonist

Question 18

When are cortisol levels measured?

Answer 18

9am if normal circadian rhythm (need to adjust for night shift workers)

Question 19

When are testosterone levels measured?

Answer 19

9am
testosterone levels highest in morning + drops during day
should be fasted -> meals can lower testosterone

Question 20

What type of test should be done if you are suspecting hormone excess?

Answer 20

suppression test

Question 21

What type of test should you do if you are suspecting hormone deficiency?

Answer 21

stimulation test

Question 22

Addison’s diagnostic test

Answer 22

ACTH stimulation

Question 23

Cushing’s diagnostic test

Answer 23

dexamethasone suppression

Question 24

Acromegaly diagnostic test

Answer 24

OGTT

Question 25

Why can cortisol levels not be measured if a patient is on the contraceptive pill?

Answer 25

contraceptive pills increase cortisol binding globulin so cortisol levels could look high when they're not need to be off pill 6 weeks before measurement

Question 26

What drugs affect prolactin levels?

Answer 26

antipsychotics metoclopramide

Question 26

Treatment of non-functioning pituitary tumours

Answer 26

lost hormones need to be replaced: cortisol must be replaced that day surgery for tumours that are growing or causing mass effect pituitary radiotherapy - helps reduce recurrence rate

Question 27

What is synthetic vasopressin?

Answer 27

desmopressin

Question 28

Name functioning tumours of the pituitary gland in order of incidence

Answer 28

prolactinoma acromegaly Cushing's TSHoma GNoma

Question 29

What is meant by the term functioning tumour?

Answer 29

produce hormones

Question 30

What is prolactinoma a tumour of?

Answer 30

lactotroph cells

Question 31

Macroprolactinoma size

Answer 31

>1cm

Question 32

Do prolactinomas need surgery?

Answer 32

no very responsive to dopamine agonists

Question 33

What causes acromegaly?

Answer 33

tumour of somatotroph cells producing GH

Question 34

Acromegaly symptoms and possible complications

Answer 34

gigantism - pre-puberty post-puberty: - sweating - swelling - growth of soft tissues increased mortality, vascular disease, cardiomyopathy, respiratory disease, OA, malignancy and colonic polyps, sleep apnoea

Question 35

Acromegaly treatment

Answer 35

pituitary surgery (macroadenoma) pituitary irradiation long-acting somatostatin analogues if mild/co-secrete PRL - dopamine agonists eg. cabergoline IGF1 receptor antagonists

Question 36

What causes Cushing's disease?

Answer 36

corticotroph adenoma leads to increased ACTH, loss of diurnal rhythm and increase in adrenal cortisol production

Question 37

Cushing's disease symptoms

Answer 37

central obesity abdominal striae thin skin proximal myopathy hypertension osteoporosis impaired glucose tolerance/diabetes depression

Question 38

What is the difference between Cushing's disease and Cushing's syndrome?

Answer 38

Cushing disease occurs when Cushing syndrome is caused by an ACTH-producing pituitary tumor, whereas Cushing syndrome is the set of symptoms that results when there is a surplus of cortisol in the body

Question 39

How is Cushing's syndrome diagnosed?

Answer 39

24h urinary free cortisol x2 low dose dexamethasone suppression test midnight cortisols + plasma ACTH levels CT adrenals MRI pituitary Inferior petrosal sinus sampling

Question 40

Treatment of Cushing's disease?

Answer 40

pituitary surgery if you can locate a pituitary tumour adrenal surgery if emergency, or very difficult to control disease pituitary irradiation after surgery if not cured drugs to prepare for surgery/waiting for radiotherapy to be effective: - metyrapone, ketoconazole - block adrenal steroid production treat complications - eg. diabetes, hypertension, hypopituitarism

Question 41

What is pituitary apoplexy?

Answer 41

sudden bleed into an existing pituitary tumour

Question 42

Pituitary apoplexy symptoms

Answer 42

sudden headache vomiting collapse visual field loss ophthalmoplegia

Question 43

How does the posterior pituitary appear on MRI?

Answer 43

bright spot - physiological (if anterior pituitary is bright this is pathological)

Question 44

What does the posterior pituitary produce?

Answer 44

ADH (antidiuretic hormone) oxytocin

Question 45

Diabetes insipidus symptoms

Answer 45

insatiable thirst polyuria (cannot concentrate urine)

Question 46

How is diabetes insipidus diagnosed?

Answer 46

plasma and urine osmolalities - inappropriately dilute urine water deprivation test if doubt remains

Question 47

Diabetes insipidus treatment

Answer 47

intranasal or oral desmopressin at night