Pituitary tumours

Question 1

Which endocrine cells secrete growth hormone?

Answer 1

Somatrophs

Question 2

Lactotrophs release which hormone?

Answer 2

Prolactin

Question 3

Which endocrine cells secrete thyroid stimulating hormone?

Answer 3

Thyrotrophs

Question 4

Which hormones are secreted by the gonadotrophs?

Answer 4

Luteinising hormone (LH)
Follicle stimulating hormone (FSH)

Question 5

Which cells secrete ACTH?

Answer 5

Corticotrophs

Question 6

Acromegaly is related to which endocrine cell?

Answer 6

Somatotrophs

Question 7

A tumour of the lactotrophs is referred to as?

Answer 7

Prolactinoma

Question 8

A TSHoma is of what cell?

Answer 8

Thyrotrophs

Question 9

What is a gonadotrophinoma?

Answer 9

Tumour of gonadotrophs

Question 10

Which endocrine cells can be associated with Cushing’s disease?

Answer 10

Corticotroph adenoma

Question 11

What is the classification of a microadenoma?

Answer 11

<1Omm (1cm)

Question 12

What is the classification of a macroadenoma?

Answer 12

> 1cm (10mm)

Question 13

What are the two types of a pituitary tumour in terms of function?

Answer 13

Excess secretion of a specific pituitary hormone

No excess secretion of pituitary hormone (non-functioning adenoma)

Question 14

How is the mitotic index of a pituitary adenoma measured?

Answer 14

ki67 index benign is <3%

Question 15

What mitotic index classifies a pituitary adenoma as benign?

Answer 15

<3%

Question 16

Which hormone inhibits the pulsatile action of kisspeptin neurones?

Answer 16

Prolactin

Question 17

What parameter of serum prolactin is associated with a prolactinoma?

Answer 17

> 5000mu/L

serum prolactin is proportional to tumour size

Question 18

What are the clinical presentations of a prolactinoma?

Answer 18

menstrual disturbance
erectile dysfunction
Reduced libido
Galactorrhoea
Subfertility

Question 19

What are the physiological causes of an elevated prolactin?

Answer 19

Pregnancy/breast feeding
Stress; exercise, seizure, venepuncture (stress induced can lead to an increase in prolactin levels)
Nipple/chest wall stimulation

Question 20

What are the pathological causes of elevated prolactin?

Answer 20

Primary hypothyroidism (Due to increased TRH release)
Polycystic ovarian syndrome 
Chronic renal failure

Question 21

What are the latrogenic causes of elevated serum prolactin?

Answer 21

Antipsychotics
Selective serotonin re-uptake inhibitors
Anti-emetics
High dose oestrogen 
opiates

Question 22

What is macroprolactin?

Answer 22

A polymeric form of prolactin

An antigen-antibody complex of monomeric prolactin and IgG (normally <5% of circulating prolactin)

Question 23

How is the majority of prolactin transported within the serum?

Answer 23

Monomeric prolactin that is biologically active

Question 24

What are the two possible outcomes of an elevation of serum prolactin yet there are no clinical consistent features?

Answer 24

Macroprolactin

Stress of venipuncture

Question 25

How can a stress of venepuncture be excluded from true elevation in serum prolactin?

Answer 25

Exclude by a cannulated prolactin series | Sequential serum prolactin measurement 20 minutes apart with an indwelling cannula to minimise venepuncture stress.

Question 26

How is a true pathological elevation of serum prolactin diagnosed?

Answer 26

Conduct pituitary MRI

Question 27

What is the first line of treatment in regards to prolactinomas?

Answer 27

Dopamine receptor agonists (cabergoline or bromocriptine)

Question 28

What is the aim with using cabergoline?

Answer 28

Normalise serum prolactin and shrink prolactinoma

Question 29

How do dopamine receptor agonists work?

Answer 29

Bind to D2 receptors on lacotrophs therefore exerting an inhibitory effect on prolactin release

Question 30

What are the symptoms associated with acromegaly?

Answer 30

``` Sweatiness Headache Coarsening of facial features Macroglossia Prominent nose Large jaw - prognathism Increased hand and feet size Snoring & obstructive sleep apnoea Hypertension Impaired glucose tolerance/diabetes mellitus ```

Question 31

Which factor is released from the liver upon stimulation of growth hormone?

Answer 31

IGF-1 | and IGF-2

Question 32

How can acromegaly be diagnosed?

Answer 32

Elevated serum IGF-1 Failed suppression of GH following oral glucose load (OGTT) - paraxodical rise

Question 33

What is the main risk that is increased in patients with acromegaly?

Answer 33

Increased cardiovascular risk

Question 34

What is the first line of treatment in patients with acromegaly?

Answer 34

Trans-sphenoidal pituitary surgery

Question 35

What pharmacological treatments can be prescribed for acromegaly?

Answer 35

Somatosatin analogues (octreotide) Dopamine agonists (cabergoline) -GH secreting pituitary tumours frequently express D2 receptors.

Question 36

What are the clinical features Cushing's syndrome?

Answer 36

``` Mental changes (depression) Osteoporosis Impaired glucose tolerance (diabetes) High blood pressure Proximal myopathy Red cheeks Fat pads Thin skin Easy bruising Moon face Purple striae Pendulous abdomen Poor wound healing ```

Question 37

What is the most common cause of Cushing's syndrome?

Answer 37

Oral corticosteroids

Question 38

What are the four causes of Cushing's disease?

Answer 38

Oral consumption of corticosteroids Pituitary dependent Cushing's disease (pituitary adenoma) Ectopic ACTH (lung cancer) Adrenal adenoma or carcinoma

Question 39

What are ACTH dependent forms of Cushing's disease?

Answer 39

``` Corticotroph adenoma Ectopic ACTH (lung cancer) ```

Question 40

What are the ACTH independent causes of Cushing's syndrome?

Answer 40

Oral corticosteroids | Adrenal adenoma or carcinoma

Question 41

What is Cushing's syndrome?

Answer 41

An excess cortisol

Question 42

What is Cushing's disease?

Answer 42

Due to corticotroph adenoma secreting ACTH

Question 43

How is Cushing's disease investigated?

Answer 43

Elevation of 24h urine free cortisol - increased cortisol secretion Elevation of late light cortisol - salivary or blood test - loss of diurnal rhythm Failure to suppress cortisol after oral dexamethasone (exogenous glucocorticoid) increased cortisol secretion.

Question 44

What are the clinical features often presented alongside a non-functioning pituitary adenoma?

Answer 44

Bitemporal hemianopia