Pituitary II

Question 1

What causes Cushing’s syndrome?

Answer 1

Excess cortisol

Question 2

What do the excess mineralocorticoid and androgen of Cushing’s syndrome cause?

Answer 2

Mineralocorticoid = hypertension, oedema
Androgen = virilism, hirsutism, acne, oligo/ammenorrhoea

Question 3

What does the altered lipid and carbohydrate metabolism that occurs in Cushing’s syndrome cause?

Answer 3

Diabetes and obesity

Question 4

How can Cushing’s syndrome alter the patient’s psyche?

Answer 4

Psychosis and depression

Question 5

How does the protein loss that occurs during Cushing’s syndrome manifest?

Answer 5

Myopathy, wasting, osteoporosis, fractures, thin skin, striae, bruising

Question 6

What symptoms characterise Cushing’s syndrome?

Answer 6

Thin skin, proximal neuropathy, frontal balding in women, conjunctival oedema, osteoporosis

Question 7

How is Cushing’s syndrome screened for?

Answer 7

Overnight 1mg dexamethasone suppression test = >130nmol/L is diagnostic
Urine free cortisol = total >250, cortisol/creatine ratio >25
Diurnal variation = loss of variation

Question 8

What is the definitive test for Cushing’s syndrome?

Answer 8

Low dose DST, 2 day 2mg/day dexamethasone suppression test = cortisol >130nmol/L after 6hrs

Question 9

What is the aetiology of Cushing’s syndrome?

Answer 9

Pituitary (majority) = Cushing’s disease (all other are Cushing’s syndrome)
Adenoma of adrenal
Ectopic ACTH production = thymus, lungs, pancreas
Pseudo = alcohol, depression, steroids

Question 10

What does the CRH test show in Cushing’s syndrome?

Answer 10

50% increase in ACTH, 20% increase in cortisol (suggestive of pituitary struggle)

Question 11

What is the treatment of pituitary Cushing’s (Cushing’s disease)?

Answer 11

Hypophysectomy (transsphenoid route) and external radiotherapy if recurs, bilateral adrenalectomy

Question 12

How are ectopic and adrenal Cushing’s syndrome treated?

Answer 12

Adrenal = adrenalectomy
Ectopic = remove source or bilateral adrenalectomy

Question 13

What drugs are used to treat Cushing’s syndrome?

Answer 13

Metyrapone = if other treatments fail/while waiting for radiotherapy, side effects common
Ketoconazole = hepatotoxic
Pasireotide LAR = 10-20mg monthly

Question 14

What hormones are affected by anterior hypopituitarism?

Answer 14

GH (growth failure), TSH (hypothyroidism), LH/FSH (hypogonadism), ACTH (hypoadrenal)

Question 15

What occurs in posterior hypopituitarism?

Answer 15

Diabetes insipidus

Question 16

What can cause hypopituitarism?

Answer 16

Pituitary tumours, brain tumours, iatrogenic (surgery), TB, histiocytosis X, sarcoidosis, polyarteritis, trauma, secondary metastases, syphilis, meningitis, autoimmune, infection

Question 17

What are some symptoms of anterior hypopituitarism?

Answer 17

Menstrual irregularities, infertility and impotence, gynaecomastia, abdominal obesity, loss of facial hair, loss of axillary and pubic hair, dry skin and hair, hypothyroid faces, growth retardation

Question 18

How can hypopituitarism be investigated?

Answer 18

Check anterior pituitary hormones

Question 19

What is the replacement therapy for hypopituitarism?

Answer 19

Thyroxine = 100-150mcg/day
Hydrocortisone = 10-25mg/day, split 2-3 times per day
ADH = desmospray (nasal) or desmopressin tablets
GH = nightly
Sex steroids

Question 20

What are the benefits of growth hormone (GH) replacement in hypopituitarism?

Answer 20

Given by daily SC injection = improves well being and quality of life, decreases abdominal fat, increase muscle mass/strength/exercise capacity/stamina, improves cardiac function, improves bone density

Question 21

How is testosterone replacement given in hypopituitarism?

Answer 21

IM injection every 3-4 weeks (sustanon), skin gel (testogel, tostran), prolonged IM injection 10-14 weeks (nebido)

Question 22

What are the risks of testosterone replacement?

Answer 22

Prostate enlargement = monitor PR exam and PSA at start
Polycythaema = cause risk of stroke/MI, monitor FBC
Hepatitis (oral tablets only) = monitor LFTs

Question 23

What are the causes of diabetes insipidus?

Answer 23

Familial = isolated in most cases, DIDMOAD
Acquired = idiopathic (50%), trauma, tumour, sarcoid, meningitis

Question 24

How are water deprivation tests carried out?

Answer 24

For 8-12hrs

Check serum and urine osmolarities for 8h and then 4h after giving IM DDAVP

Question 25

What do the results of a water deprivation test indicate?

Answer 25

If urine/serum osmol ratio >2 then is normal (otherwise DI)

If low and improves after DDAVP then is due to cranial DI (deficiency of DDAVP and not nephrogenic DI)

Question 26

How is diabetes insipidus treated?

Answer 26

Desmospray = nasally, 10-60mcg/day
Desmopressin oral tablets = 100-1000mcg per day
Desmopressin injection = 1-2mcg IM per day (emergency or post-pituitary surgery)