Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

4th year passmedicine by topic > Pituitary > Flashcards

Pituitary Flashcards

1
Q

What is acromegaly?

A

excess growth hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Causes of acromegaly?

A

secondary to a pituitary adenoma in over 95% of cases. A minority of cases are caused by ectopic GHRH or GH production by tumours e.g. pancreatic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Symptoms of acromegaly?

A

coarse facial appearance, spade-like hands, increase in shoe size
large tongue, prognathism, interdental spaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What causes excessive sweating and oily skin in acromegaly?

A

Sweat gland hypertrophy?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are features of pituitary tumour?

A

hypopituitarism, headaches, bitemporal hemianopia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a common hormone imbalance with acromegaly?

A

raised prolactin in 1/3 of cases → galactorrhoea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which genetic disorder is a ssoc with acromegaly?

A

6% of patients have MEN-1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Complications of acromegaly?

A

hypertension
diabetes (>10%)
cardiomyopathy
colorectal cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Growth hormone (GH) levels diagnostic of acromegaly

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Acromegaly first line test?

A

Serum IGF-1 levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Acromegaly diagnostic tx?

A

oral glucose tolerance test (OGTT) with serial GH measurements

The OGTT test is recommended to confirm the diagnosis if IGF-1 levels are raised.

suppression of GH to < 1 μg/L following documented hyperglycemia during an oral glucose load.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Acromegaly - what can be used to monitor disease?

A

Serum IGF-1 may also be used to monitor disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe results of Oral glucose tolerance test in normal vs acromegaly?

A

in normal patients GH is suppressed to < 2 mu/L with hyperglycaemia
in acromegaly there is no suppression of GH
may also demonstrate impaired glucose tolerance which is associated with acromegaly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

A pituitary MRI may demonstrate a pituitary tumour in acromegaly

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

first line mx acromegaly?

A

Trans-sphenoidal surgery is the first-line treatment for acromegaly in the majority of patients.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

second line mx acromegaly?

A

If a pituitary tumour is inoperable or surgery unsuccessful then medication may be indicated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

medications used in acromegaly?

A

somatostatin analogue
pegvisomant
dopamine agonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mechanism of somatostatin analogue

A

directly inhibits the release of growth hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Example of somatostatin analogue

A

octreotide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How effective is somatostatin analogue in acromegaly?

A

effective in 50-70% of patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mechanism of pegvisomant

A

GH receptor antagonist - prevents dimerization of the GH receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How effective is pegvisomant in acromegaly?

A

very effective - decreases IGF-1 levels in 90% of patients to normal
doesn’t reduce tumour volume therefore surgery still needed if mass effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is pegvisomant administered?

A

once daily s/c administration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Pegvisomant reduces tumour volume in acromegaly

A

false

doesn’t reduce tumour volume therefore surgery still needed if mass effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Example of dopamine agonists?

A

for example bromocriptine, ropinirole, cabergoline, apomorphine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How effectuve are dopamine agonists in acromegaly?

A

effective only in a minority of patients

27
Q

dopamine agonists are the first effective medical treatment for acromegaly, however now superseded by somatostatin analogues

A

true

28
Q

When is external irradiation used in acromegaly?

A

External irradiation is sometimes used for older patients or following failed surgical/medical treatment

29
Q

ergot-derived dopamine receptor agonists (bromocriptine, cabergoline, ) have been associated with

A

pulmonary, retroperitoneal and cardiac fibrosis

ESR, creatinine and chest x-ray should be obtained prior to treatment and patients should be closely monitored

30
Q

Adverse side effects of dopamine receptor agonists?

A

nausea/vomiting
postural hypotension
hallucinations
daytime somnolence

31
Q

What is Prolactinoma?

A

Prolactinomas are a type of pituitary adenoma, a benign tumour of the pituitary gland.

32
Q

Prolactinoma can be classified according to:

A

size

hormonal status

33
Q

Prolactinoma size classification

A

a microadenoma is <1cm and a macroadenoma is >1cm

34
Q

Prolactinoma hormonal status?

A

a secretory/functioning adenoma produces and excess of a particular hormone and a non-secretory/functioning adenoma does not produce a hormone to excess

35
Q

What is the commonest type of pituitary adenoma?

A

Prolactinoma

36
Q

Features of excess prolactin

A

men: impotence, loss of libido, galactorrhoea
women: amenorrhoea, infertility, galactorrhoea, osteoporosis

37
Q

Diagnosis of Prolactinoma?

A

MRI

38
Q

Mx of Prolactinoma?

A

in the majority of cases, symptomatic patients are treated medically with dopamine agonists (e.g. cabergoline, bromocriptine) which inhibit the release of prolactin from the pituitary gland

surgery is performed for patients who cannot tolerate or fail to respond to medical therapy. A trans-sphenoidal approach is generally preferred unless there is a significant extra-pituitary extension

39
Q

Prolactin is secreted by

A

anterior pituitary gland

40
Q

which hormone acts as the primary prolactin releasing inhibitory factor

A

Dopamine

hence dopamine agonists such as bromocriptine may be used to control galactorrhoea.

41
Q

Causes of raised prolactin

A 
prolactinoma
pregnancy
oestrogens
physiological: stress, exercise, sleep
acromegaly: 1/3 of patients
polycystic ovarian syndrome
primary hypothyroidism
42
Q

Why can hypothyroidism cause raised prolactin?

A

due to thyrotrophin releasing hormone (TRH) stimulating prolactin release

43
Q

Drug causes of raised prolactin

A

metoclopramide, domperidone
phenothiazines
haloperidol
very rare: SSRIs, opioids

44
Q

What is pituitary adenoma?

A

A pituitary adenoma is a benign tumour of the pituitary gland.

45
Q

How common is pituitary adenoma?

A

They are common (10% of all people1) but in most cases will never be found (asymptomatic) or are found as an incidental finding. They account for around 10% of adult brain tumours

46
Q

Pituitary adenomas can be classified according to:

A 
size (a microadenoma is <1cm and a macroadenoma is >1cm)
hormonal status (a secretory/functioning adenoma produces and excess of a particular hormone and a non-secretory/functioning adenoma does not produce a hormone to excess)
47
Q

After prolactinomas what is common pituitary adenoma?

A

non-secreting adenomas are the next most common, then GH secreting and then ACTH secreting adenomas.

48
Q

Pituitary adenomas typically cause symptoms by

A

excess of a hormone

depletion of a hormone(s) (due to compression of the normal functioning pituitary gland)

stretching of the dura within/around pituitary fossa (causing headaches)##

compression of the optic chiasm (causing a bitemporal hemianopia due to crossing nasal fibers)

49
Q

pituitary adenomas, particularly microadenomas, can be an incidental finding on neuroimaging and therefore called a

A

pituitary incidentaloma’.

50
Q

Investigation for pituitary adenoma

A

a pituitary blood profile (including: GH, prolactin, ACTH, FH, LSH and TFTs)
formal visual field testing
MRI brain with contrast

51
Q

Differential diagnoses pituitary adenoma

A 
pituitary hyperplasia
craniopharyngioma
meningioma
brain metastases
lymphoma
hypophysitis
vascular malformation (e.g. aneurysm)
52
Q

Treatment of pituitary adenoma

A

hormonal therapy (e.g. bromocriptine is the first line treatment for prolactinomas)

surgery (e.g. transsphenoidal transnasal hypophysectomy) e.g. if progression in size

radiotherapy

53
Q

MEN 1

A

Parathyroid (95%): hyperparathyroidism due to parathyroid hyperplasia
Pituitary (70%)
Pancreas (50%): e.g. insulinoma, gastrinoma (leading to recurrent peptic ulceration)

Also: adrenal and thyroid

54
Q

MEN 2A

A

Medullary thyroid cancer (70%)

2 P’s
Parathyroid (60%)
Phaeochromocytoma

55
Q

MEN 2B

A

Medullary thyroid cancer

1 P
Phaeochromocytoma

Marfanoid body habitus
Neuromas

56
Q

Cause of Men1

A

MEN1 gene

57
Q

MEN 1 presentation most cmmonly

A

Most common presentation = hypercalcaemia

58
Q

Cause MEN 2

A

RET oncogene

59
Q

HOW is MEN inherited

A

autosomal dominant

60
Q

Drug causes of gynaecomastia - commonest drug

A

spironolactone

61
Q

Drug causes of gynaecomastia

A 
spironolactone (most common drug cause)
cimetidine
digoxin
cannabis
finasteride
GnRH agonists e.g. goserelin, buserelin
oestrogens, anabolic steroids
62
Q

Very rare drug causes of gynaecomastia

A 
tricyclics
isoniazid
calcium channel blockers
heroin
busulfan
methyldopa
63
Q

Causes of gynaecomastia

A 
physiological: normal in puberty
syndromes with androgen deficiency: Kallman's, Klinefelter's
testicular failure: e.g. mumps
liver disease
testicular cancer e.g. seminoma secreting hCG
ectopic tumour secretion
hyperthyroidism
haemodialysis
drugs

4th year passmedicine by topic (96 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions