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Metabolism, Endocrinology, Haematology > Endocrinology Session 3 CLINICAL > Flashcards

Endocrinology Session 3 CLINICAL Flashcards

1
Q

How do pituitary tumours present?

A
  • Effects on local structures which cause headaches, visual losses
  • Hyper/hypo-secretion of hormones from the pituitary glands
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2
Q

What nerves can be compressed and affected by pituitary tumours?*

A
  • Optic chiasm (vision)
  • Oculomotor nerve III - eye movement
  • Trochlear nerve IV ^^
  • Internal carotid artery (blood supply affected when compressed)
  • Abducens VI nerve - lateral eye movement
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3
Q

What happens when a pituitary tumour grows superiorly?

A
  • Pressure on the optic chiasm

- Will cause visual field loss

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4
Q

What happens when a pituitary tumour grows laterally?*

A
  • Pain and double vision
  • Sinus inversion
  • Cranial nerve palsy
  • Eye compressive problems
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5
Q

What is bitemporal hemianopia?*

A

Condition caused by a pituitary tumour where the person cannot see laterally left or right due to the tumour compressing the optic chiasm

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6
Q

What happens when the cavernous sinus is invaded?*

A
  • Headache and double vision

- Often appears with third nerve palsy: left sided eye compressive problems, eyelid drooping

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7
Q

How is the pituitary gland controlled by the hypothalamus?

A

Positive control - GH, LH/FSH, TSH, ACTH

Negative control - Prolactin

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8
Q

How do pituitary tumours lead to disorders?*

A

The pituitary tumour will prevent the entry of hormones that are under positive control, so they will be deficient

The tumour will also prevent the inhibition of prolactin, leading to disinhibition hyperprolactinaemia

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9
Q

What is disinhibition hyperprolactinaemia and what causes it?

A
  • Caused by a pituitary tumour
  • Prevents inhibition of prolactin production
  • Buildup of prolactin
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10
Q

What is the first hormone to become deficient and what are the symptoms of this deficiency in adult and children?

A

Growth hormone

  • Adults: less muscle growth, reduced quality of life
  • Children: short stature
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11
Q

What is gonadotropin deficiency and how does it present?

A

Deficiency in luteinising hormone and follicle-stimulating hormone, which stimulate oestrogen/progesterone production

  • Low testosterone in men
  • Delayed puberty in children
  • Loss of secondary sexual characteristics in adults
  • Loss of periods in women (early sign)
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12
Q

What are the symptoms of low testosterone in men?

A
  • Association with prostate cancer
  • Hair loss
  • Gynaecomastia
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13
Q

What are the symptoms of TSH deficiency?

A
  • Low thyroid hormones
  • Weight gain
  • Low T4
  • Non-elevated TSH
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14
Q

What are the symptoms of ACTH deficiency and why can this deficiency quickly become fatal?

A
  • Low cortisol
  • Dizziness and fatigue
  • Low sodium and blood pressure

People can go into hypoadrenal crisis (severe adrenal insufficiency)

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15
Q

Which hormones are commonly produced when the pituitary functions abnormally and why?

A

Cell hyperplasia occurs, so there are many cells producing many hormones

  • Prolactin
  • GH
  • ACTH overproduction is common
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16
Q

What can cause TSH and LH/FSH deficiency?

A

Gonadotropinomas

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17
Q

What can a basal blood test be sufficient in diagnosing?

A

Serum prolactin, TSH, LH, FSH, Testosterone and oestradiol

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18
Q

Why is a dynamic blood test needed for 0900 cortisol?

A

Cortisol levels fluctuate during the day (eg. high in the morning and low in the evening) therefore it’s important to see how they change.

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19
Q

What are the ways of dynamically assessing HPA and GH excesses?

A

Stimulation test if there is a suspected deficiency

Suppression test if there is a suspected excess

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20
Q

How can a deficiency/excess in the adrenal axis be measured?

A

Deficiency: direct stimulation by synthetic ACTH
Response to insulin stress test

Excess: suppressing ACTH axis with steroids

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21
Q

How can a deficiency/excess in the GH axis be measured?

A

Deficiency: response to hypoglycaemic stress

Excess: suppressing the GH axis with glucose load (glucose tolerance test)

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22
Q

What happens if the light can’t move through the optic nerve due to the tumour?*

A

Anopsia on the side where the tumour blocks it

23
Q

What happens if the tumour grows in the optic chiasm?*

A

Light cannot move through due to the chiasmal region
- Bitemporal hemianopsia (loss of visual field)
Always strongly suggests a pituitary tumour

24
Q

What happens if the tumour grows in the optic tract?*

A

Homonymous hemanopia (limited vision in both eyes on the same side)

25
Q

How do you assess for pituitary tumours?

A

MRI

26
Q

What is a prolactinoma and what is the difference between macro-adenoma and micro-adenoma?*

A

Prolactin-secreting pituitary tumour

  • Macro-adenoma: > 1cm
  • Micro-adenoma: < 1cm
27
Q

What can a prolactinoma cause?

A

Disinhibition prolactinaemia (higher prolactin levels)

28
Q

How are prolactinomas treated?

A

Tablets (not an operation, despite the size)

Treated with dopamine agonists as dopamine inhibits prolactin

29
Q

How is prolactin secretion directly inhibiting LH?*

A

Prolactin stops LH acting on ovary/testes

30
Q

What are the symptoms of hyperprolactinaemia in women?

A
  • Menstrual disturbance
  • Fertility problems
  • Galactorrhoea (milk production outside of pregnancy)
31
Q

What are the symptoms of hyperprolactinaemia in men?

A
  • Usually caused by macroadenomas
  • Non specific (low testosterone)
  • Visual loss
32
Q

Why do NFPTs cause prolactin disinhibition?

A

Prolactin is under direct inhibitory control by dopamine, and anything blocking the stalk will prevent dopamine to binding to the receptors that will stop prolactin synthesis in the anterior pituitary and therefore its release

33
Q

When is the hyperprolactinaemia most likely to be caused by a non-functioning tumour, and when by prolactinomas, and why is that important?

A
  • Prolactin <5000 = mostly due to disinhibition
  • Prolactin > 5000 = mostly due to prolactinoma

Important as prolactinomas are treated by medication but non-functioning pituitary tumours are treated surgically

34
Q

What is a non-functioning pituitary adenoma?

A

A tumour that does not secrete biologically active hormones & may secrete inactive hormones (eg. ACTH, LH/FSH

35
Q

Why do people with non-functioning pituitary adenomas experience symptoms?

A
  • Due to low hormones (will have blood tests showing ‘hypopituitarism’)
  • Due to mass effect (eg. visual loss)
36
Q

How are prolactinomas treated?

A

Dopamine agonists to stimulate D2 receptor (bromocriptine)

37
Q

What must always be checked in a patient who has high prolactin levels?

A
  • If they are on medications that are dopamine antagonists (eg. anti-sickness and anti-psychotic drugs)
  • If patient is not pregnant
38
Q

What is acromegaly?*

A

’ Large extremities ‘ - giant hands and feet mostly (head, too)
Gradual changes in features over a few years

39
Q

What causes acromegaly?

A

Growth hormone-secreting pituitary tumour

40
Q

What are the complications of untreated acromegaly?

A
  • Premature CVS death
  • Increased risk of colonic tumours
  • Increased risk of thyroid cancer
  • Disfiguring body changes
  • Hypertension
  • Diabetes
41
Q

What tests can be used to confirm acromegaly?

A
  • Elevated IGF-1 levels
  • GH day curve
  • Oral glucose tolerance test with GH response
42
Q

How is acromegaly treated?

A
  • Surgical removal of tumour (trans-sphenoidal hypophysectomy)
  • Additional treatment if tumour in cavernous sinus
43
Q

What is the additional treatment that can treat acromegaly?*

A

Dopamine antagonists (bromocriptine) and somatostatin analogues (ocreotide) = Reduce GH secretion

Pegvisomant = Block GH receptor

  • External beam radiotherapy = multiple short bursts, several weeks
  • Gamma knife = one high concentration beam
44
Q

What is Cushing’s disease?

A

An excess of cortisol caused by an ACTH-secreting pituitary tumour

45
Q

What are the symptoms and signs of Cushing’s disease?*

A
  • Round, pink face
  • Round abdomen
  • Skinny and weak arms and legs
  • Thin skin, so easy bruising
  • Abdominal striae
  • High BP and diabetes
  • Osteoporosis
46
Q

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

A

Cushing’s syndrome is caused by other pathologies (eg. steroid medication causing high cortisol), whereas Cushing’s disease is caused by a pituitary tumour

47
Q

What is diabetes insipidus?*

A

A condition where large quantities of pale urine are passed, with extreme thirst due to fluid loss (the body cannot reabsorb water)

Problems with anti-diuretic hormones (ADH) secretion, so water is not being reabsorbed into body

48
Q

What is cranial diabetes insipidus?

A

DI caused by vasopressin deficiency caused by pituitary disease (inflammation/malignancy/infection)

49
Q

What is nephrogenic diabetes insipidus?

A

DI caused by vasopressin resistance due to kidney disease

50
Q

What are the consequences of untreated diabetes insipidus?

A
  • Severe dehydration
  • Hypernatraemia
  • Reduced consciousness, coma, death
51
Q

How to treat cranial DI?

A
  • Synthetic vasopressin

- Desmopressin: nasal spray, tablets, injection

52
Q

What is pituitary apoplexy?*

A

A sudden vascular event in a pituitary tumour: either a rupture and bleeding within the tumour (haemorrhage) or the cut off of the blood supply (infarction).

53
Q

How does pituitary apoplexy present?

A
  • Sudden onset headache
  • Cranial third nerve palsy
  • Double vision
  • Visual field loss
  • Hypopituitarism (esp. cortisol deficiency)
  • PROMPT DIAGNOSIS NEEDED

Metabolism, Endocrinology, Haematology (16 decks)

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