The pituitary gland clinical case

Question 1

Pituitary diseases resulting from hypersecretion of GH, ACTH and prolactin (tumours)

Answer 1

GH - acromegaly

ACTH - Cushing’s disease

Prolactin - hyperprolactinaemia

Question 2

Which hormones cause pituitary diseases due to hyposecretion of them

Answer 2

Anterior - (FSH/LH, GH, ACTH, TSH)

Posterior - Vasopressin

Question 3

A space occupying pituitary disease can cause compression of what important structure?

Answer 3

Optic chiasm

Question 4

Clinical features of acromegaly (gigantism) (6)

Answer 4

‘spade like’ hands (rings)

wide feet (shoes)

coarse facial features

thick lips & tongue

carpal tunnel syndrome - pressure on nerve in your wrist. It causes tingling, numbness and pain in your hand and fingers.

sweating

Question 5

Complications associated with acromegaly (8)

Answer 5

Headache

Chiasmal compression

Diabetes M

Hypertension

Cardiomyopathy

Sleep apnoea

Colonic polyps + Cancer

Accelerated osteoarthritis

Question 6

Diagnosis of acromegaly

Answer 6

GH suppression - - Failure to suppress GH is diagnostic of acromegaly when coupled with elevated IGF1 and clinical signs of excess growth hormone.

Is the patient’s vision normal?

Pituitary tumour on MRI

Question 7

What causes acromegaly?

Answer 7

Increased secretion of GH from a pituitary tumour (99%) or hyperplasia

GH stimulates bone and soft tissue growth through increased secretion of insulin-like growth factor-1 (IGF-1)

Question 8

What is cushing’s syndrome? Main cause?

Answer 8

Clinical state produced by chronic glucocorticoid excess + loss of normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis

Main cause is oral steroids

Question 9

What is cushing’s disease?

Answer 9

Bilateral adrenal hyperplasia from an ACTH-secreting pituitary adenoma

Basically it is the collection of clinical symptoms and signs resulting from a pituitary tumour that causes excessive amounts of the hormone cortisol to be released by the adrenal glands.

Question 10

Symptoms of cushing’s syndrome

Answer 10

Weight gain

mood change

Proximal myopathy – closer to trunk

Osteoporosis

Growth arrest in children

Question 11

Clinical signs of cushing’s

Answer 11

Central obesity

Spontaneous purpura – small blood vessels burst, causing blood to pool under the skin

Moon face

Skin and muscle atrophy

Purple abdominal striae

Question 12

Can cushing’s disease cause cushing syndrome

Answer 12

yes

Not all cases of cushing’s syndrome is caused by a pituitary tumour though

Question 13

What is the action of the hormone cortisol (3)

Answer 13

Tissue breakdown – causes weakness of skin, muscle and bone

Sodium retention – may cause hypertension and heart failure

Insulin antagonism – may cause diabetes mellitus

Question 14

What are 2 causes of ACTH dependent cushing’s syndrome (endogenous)

Answer 14

Pituitary tumour (Cushing’s disease)

Ectopic ACTH secretion (eg lung carcinoid)

Question 15

What is ACTH

Answer 15

Adrenocorticotropic hormone - function of ACTH is to regulate levels of the steroid hormone cortisol released from the adrenal gland

Question 16

What are 2 causes of ACTH independent cushing’s syndrome (non-endogenous)

Answer 16

Adrenal tumour (adenoma or carcinoma)

Corticosteroid therapy (eg for asthma, IBD)

Question 17

What is the commonest hormonal disturbance of the pituitary

Answer 17

Hyperprolactinaemia

Question 18

Function of prolactin hormone

Answer 18

stimulates lactation

Question 19

What do raised levels of prolactin in the body cause?

Answer 19

Hypogonadism - diminished functional activity of the testes or the ovaries—that may result in diminished production of sex hormones.

Infertility

Osteoporosis

Question 20

Causes of hyperprolactinaemia? Touch on physiological, pharmacological and pathological aspects

Answer 20

Physiological - pregnancy, lactation, stress

Pharmacological - DA depleting and DA anatgonist drugs (neuroleptics + anti-emetics), some antidepressants

Pathological - primary hypothyroidism, pituitary lesions

Question 21

Hypopituitarism

Answer 21

Decrease in secretion of anterior pituitary hormones mainly but also posterior.

Question 22

Which anterior pituitary hormones are affected in hypopituitarism

Answer 22

FSH/LH - gonadotropins

GH - growth hormone

ACTH - acts on adrenal - cortisol

TSH - thyroid stimulating hormone

Question 23

Which posterior hormone is affected in hypopituitarism

Answer 23

vasopressin

Question 24

Clinical features of hypopituitarism in Adults (7)

Answer 24

• Tiredness
• Weight gain
• Depression
• Reduced libido
• Menstrual problems
• Skin pallor
• Reduced body hair

Question 25

Clinical features of hypopituitarism in Children (2)

Answer 25

• Reduced linear growth

* Delayed puberty

Question 26

How do somatostatin analogues work in acromegaly

Answer 26

They improve tissue overgrowth, sweating, headache, sleep apnoea in most patients.

Normalise GH and IGF-1 levels in over 50% of patients.

Induce tumour shrinkage and reduce morbidity + mortality from acromegaly.

Question 27

Adverse affects of Ocreotide and Lanreotide: Somatostatin analogues

Answer 27

Nausea

Cramps

Diarrhoea

Flatulence

Cholesterol gallstones occur in 20-30% (mostly asymptomatic)

Slow release preparations require monthly IM/SC injections

High cost

Question 28

Treatment of Pituitary tumours causing hypersecretion

Answer 28

dopamine agonists
somatostatin analogues
GH receptor analogues

Question 29

Treatment of Pituitary tumours causing hyposecretion

Answer 29

Hormone replacement: Cortisol, T4, sex steroids, GH

Desmopressin