Pituitary disease

Question 1

What are the different causes for raised prolactin?

Answer 1

Physiological: breast feeding, pregnancy, stress, sleep

Drugs: dopamine antagonists (metoclopramide), antipsychotics, antidepressants (TCAs and SSRIs)

Pathological: hypothyroidism, pituitary stalk lesion, prolactinoma (prolactin producing pit. adenoma)

Question 2

What are the clinical signs and symptoms for hyperprolactinaemia in males/females?

Answer 2

Males:

• late presentation
• galactorrhea <30%
• visual field abnormality
• headache
• impotence
• anterior pit. malfunction

Females:

• early presentation
• galactorrhea 30-80%
• menstrual irregularity
• amenorrhoea
• infertility

Question 3

What are the different investigations for prolactinoma?

Answer 3

• prolactin concentration
• MRI pituitary: pit. stalk, optic chiasm, microprolactinoma <1cm, macroprolactinoma >1cm
• visual field: bitemporal hemianopia
• pituitary function tests if other hormones affected

Question 4

What is the medical treatment of prolactinoma?

Answer 4

Dopamine agonists:

• bromocriptine 2x a day orally
• quinagolide 1x a day orally
• cabergoline 2x a week orally (less side effects)

Results: prolactin normalised/tumour shrinkage

Question 5

What is acromegaly?

Answer 5

GH excess due to somatrophadenoma, which stimulates IGF1 = mediator of GH actions

Question 6

What are the features of acromegaly?

Answer 6

• giant if before epiphyseal fusion
• thickened soft tissues (skin/jaw/hands)
• HTN/cardiac failure
• headaches
• snoring/sleep disturbance
• DM
• local pituitary affects: visual field, hypopituitarism
• early CV death

Question 7

What investigations are involved in the diagnosis of acromegaly?

Answer 7

• IGF1
• GTT
• visual field
• CT/MRI pituitary
• pituitary function tests

Question 8

What is the treatment of acromegaly?

Answer 8

pituitary surgery than retest GTT and if still >11g/l needs dopamine agonists:
-carbegoline/ocreotide/pegvisomant

Question 9

What is cushings syndrome? what is cushings disease?

Answer 9

Excess cortisol/mineralocorticoids/androgen

-cushings disease is specifically due to an excess of ACTH

Question 10

What symptoms and signs are seen in cushings syndrome?

Answer 10

Excess cortisol:

• protein loss = myopathy/wasting, osteoporosis, thin skin (bruising)
• altered carb/lipid metabolism = DM/obesity
• altered psyches = psychosis/depression

Excess mineralocorticoid = hypertension and oedema (conjunctival oedema)

Excess androgen = virilism, hirsutism, acne, oligo/amernorrhea (frontal balding in women)

Question 11

How is cushings tested for?

Answer 11

Dexamethasone suppression test

Screening:

• overnight 1mg DST = if cortisol <50nmol/l next morning is normal, if cortisol >100nmol/L is abnormal
• urine free cortisol <250 = normal
• cortisol/creatinine ratio <25 = normal
• diurnal cortisol variation

measure ACTH to see whether it is a pituitary cause or ectopic (that produces ACTH)

Diagnosis: 2 day 2mg DST

• <50nmol/L after last dose = normal
• suppress an adenoma 50%
• won’t suppress an ectopic

Question 12

What is the epidemiology of cushings syndrome?

Answer 12

rare, commoner in women 20-40yrs

Question 13

What are the different causes of cushings syndrome? split into 4 groups

Answer 13

Pituitary adenoma 80%+

Adenoma adrenal gland: benign/malignant

Ectopic: thymus, lung, pancreas (paraneoplastic secretes ACTH)

Pseudo: alcohol, depression, long term steroid medication (causes adrenal atrophy)

Question 14

Describe the management of iatrogenic cushings syndrome?

Answer 14

Patients are unable to respond to stress and need extra doses if ill/surgery

• can’t stop suddenly
• gradual withdrawal steroid

Question 15

Treatment of cushings syndrome if:

• pituitary
• adrenal
• ectopic

What drug treatment is available?

Answer 15

Pituitary:
-hypophysectomy and if recurs external radiotherapy

Adrenal:
-adrenalectomy

Ectopic:
-remove source or bilateral adrenalectomy

Drug treatment:

• metyrapone (if other treatments fail or whilst waiting for radiotherapy to work, S/E common)
• ketoconazole
• pasireotide (new somatostatin analogue)

Question 16

What affects does pan-hypopituitarism cause due to the

• anterior pituitary
• posterior pituitary

Answer 16

Anterior pituitary:

• growth failure
• hypothyroid
• hypogonadism
• hypoadrenalism

Posterior pituitary:
-Diabetes insipidus

Question 17

List causes of pan-hypopituitarism

Answer 17

¥ Pituitary Tumours

¥ Secondary metastatic lesions
Ð lung, breast

¥ Local brain tumours
Ð Astrocytoma, meningioma, glioma

¥ Granulomatous diseases
Ð TB, Histiocytosis X, sarcoidosis

¥ Vascular diseases
Ð Polyarteritis

¥ Trauma
Ð road accidents, skull fractures

¥ Hypothalamic diseases
Ð Syphilis, meningitis

¥ Iatrogenic; surgery

¥ Autoimmune;Sheenan – post pregnancy
Infection; meningitis

Question 18

What are the symptoms and signs of pan-hypopituitarism?

Answer 18

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

Question 19

How is pan-hypopituitarism tested for?

Answer 19

Baseline pituitary function tests:
¥	fT4, TSH		
¥	Oestradiol/Testosterone,  LH FSH
¥	GH, IGF-1    
¥	Prolactin

Question 20

How is pan-hypopituitarism treated?

Answer 20

¥ Thyroxine 100-150mcg/day

¥ Hydrocortisone 10-25 mg/day (am/pm)

¥ ADH Desmospray (nasal) or tablets

¥ GH nightly sc

¥ Sex Steroids Oest/prog pill for F. Testosterone for males

Always give hydrocortison first before thyroxine otherwise adrenal crisis may precipitate

Question 21

How is testesterone replaced in pan-hypopituitarism? what are the risks?

Answer 21

¥ IM injection every 3-4 weeks (sustanon)
¥ Skin gel (testogel, tostram)
¥ Prolonged IM injection 10-14 wks (nebido)
¥ (Oral tablets (restandol))

Risks:
¥ Prostate Enlargement. Does NOT cause prostate cancer but may make it grow - monitor PR exam and PSA
¥ Polycythaemia- monitor FBC
¥ Hepatitis (only for oral tablets)- monitor LFTs

Question 22

what is cranial diabetes insipidus? what is nephrogenic?

Answer 22

Cranial - lack secretion ADH (vasopressin)

Nephrogenic - renal resistance to ADH

Question 23

what causes exist for cranial diabetes insipidus?

Answer 23

¥ Familial
Ð isolated in most cases
Ð DIDMOAD (DI, DM, optic atrophy, deaf)

¥ Acquired
Ð Idiopathic in 50%
Ð Trauma; road accidents, surgery, skull fracture

¥ RARE
Ð Tumour, sarcoid, ext irradiation, meningitis

Question 24

What is the treatment for cranial diabetes insipidus?

Answer 24

¥ Desmospray
Ð nasally; 10- 60 mcg/day

¥ Desmopressin oral tablets
Ð 100-1000mcg per day

¥ Desmopressin sublingual tablets
- 60 – 360 mcg per day

¥ Desmopressin injection
Ð 1-2mcg IM per day

Question 25

What is SIADH secretion?

Answer 25

ectopic production ADH - paraneoplastic syndrome

Question 26

Pituitary adenoma: - what two different types exist? - how are they classified?

Answer 26

sporadic or assoc. with MEN1 Classify by cell type/hormone produced: -prolactin -ACTH (bilateral adrenocortical hyperplasia) -FSH/LH -GH -non-functional/hypo (prolactinoma is most common functional tumour and growth hormone secretion is second most common)

Question 27

What clinical symptoms/signs do large adenomas produce?

Answer 27

Visual field defects Pressure/atrophy of surrounding tissue infarction could lead to pan-hypo

Question 28

Craniopharyngioma: - what is this derived from? - what is the pathology? - what is the incidence? - what clinical features are seen? - prognosis?

Answer 28

Derived from remnants rathke's pouch -slow growing, often cystic, may calcify Bimodal incidence: 5-15yrs and 60-70yrs Clinical features: -headaches and visual disturbance - children may have growth retardation Prognosis: -good esp. if <5cm