ENDOCRINE - Pituitary conditions Flashcards
(94 cards)
1
Q
What is prolactin under tonic inhibition by?
A
Dopamine
2
Q
What hormones are produced by the posterior pituitary?
A
ADH
Oxytocin
3
Q
What is a pituitary adenoma?
A
Benign tumour of glandular tissue
4
Q
Which syndrome are pituitary adenomas associated with
A
MEN I/IIa
5
Q
Def microadenoma
A
<1cm
6
Q
Def macroadenoma
A
> 1cm
7
Q
What is the difference between functioning and non-functioning pituitary adenomas?
A
Functioning - secretory
8
Q
PS: non-functioning pituitary adenoma (5)
A
Bitemporal hemianopia Ocular palsies Hypopituitarism Signs raised ICP e.g. headache Hypothalamic compression Sx
9
Q
E.g.s of hypothalamic compression Sx (3)
A
Altered appetite
Thirst
Sleep/wake cycle
10
Q
PS: functioning pituitary adenoma
A
Acromegaly
Hyperprolactinaemia
Cushings
11
Q
Which hormones are rarely secreted from pituitary adenomas?
A
TSH
FSH
LH
12
Q
PS hyperprolactinaemia (5)
A
Galactorrhoea Oligo/amenorrhoea Decreased libido Subfertility in M/ ereticle dysfunction Arrested puberty - younger pt
13
Q
LT consequence hyperprolactinaemia
A
Osteoporosis
14
Q
Causes hyperprolactinaemia
A
Prolactinoma
Breast stimulation/stress
Dx induced
Idiopathic
15
Q
How is prolactinoma diagnosed?
A
Pituitary MRI
Following raised serum prolactin
16
Q
Tx hyperprolactinaemia
A
DA agonists - ropinirole/bromocriptine
17
Q
SE Ropinirole/bromocriptine (4)
A
N+V
Dizzy
Syncope
Fibrosis
18
Q
What must be monitored on Ropinirole/bromocriptine
A
Echo due to fibrosis
19
Q
XS GH in children –>
A
Gigantism
If prior to epiphyseal plate closure
20
Q
XS GH in adults –>
A
Acromegaly
21
Q
What is acromegaly almost always due to?
A
Pituitary tumour
22
Q
Rarer causes acromegaly
A
Paraneoplastic - non- pituitary tumours
23
Q
diagnosis acromegaly (2)
A
Raised IGF-1
GTT - normally suppresses GH secretion. Acromegaly - [ ] = 2mcg/ml at 2hrs
24
Q
What does IGF-1 represent
A
GH levels over 24hrs
25
Sx acromegaly (9)
```
Change in appearance
Increased hand/foot size
Tired
XS sweating
Loss libido
Sx DM
Headaches
Visual deterioration
Sx hypopituitarism
```
26
Signs acromegaly (9)
```
Protruding mandible
Prominent supraorbital ridge
Interdental separation
Large tongues
Spade-llike hands/feet
Tight rings
VF defects
HTN
Hypopituitarism
```
27
Mx acromegaly
Somatostatin analogues to shrink tumour
| Transphenoidal surgery
28
What is Cushing's syndrome due to
Increased levels of glucocorticoid
29
Most common cause Cushings syndrome
Exogenous administration of steroids
| Or XS endogenous secretions ACTH
30
ACTH dependent causes Cushings (2)
Cushings disease
| Ectopic ACTH - non-pituitary ACTH secreting tumour
31
ACTH independent causes Cushings (2)
XS adrenal cortisol production - e.g. b.c adrenal tumour
| Steroids
32
What is Cushings disease
Increased ACTH from the pituitary gland
33
Sx Cushings (= MOON FACE)
```
Menstrual changes
Obesity (central) + striae
Osteoporosis
Neurosis/depression
Facial plethora
Altered mm (proximal myopathy)
Calor skin
Elevated BP (HTN)
```
34
What electrolyte disturbance may occur in Cushings (+ why)
Hypokalaemia
| B/c of mineralcorticoid activity of cortisol
35
Diagnosis Cushings (3 tests)
1) Confirm raised cortisol w/ overnight dexamethasone suppression test
2) DDx ACTH indepedent + dependent causes - 9am + midnight plasma ACTH ((+ cortisol) levels
3) Which type of ACTH dependent is it? Low + high dose dexamethasone suppression test
36
Details of Overnight dexamethasone suppression test
Out pt
1mg PO dexamethasone given at night
Serum cortisol checked before + at 8am
Norm: -ve feedback --> cortisol levels decrease
Cushings: failure to suppress cortisol secretion
37
Details of 9am and midnight plasma ACTH (+cortisol) levels
If ACTH depressed/undetecable = adrenal cause likely
| If ACTH is detectable = either pituitary or ectopic source
38
Details of low + high dose dexamethasone suppression test
Dexamethasone 2mg/6hr PO for 2d
Measure plasma + urinary cortisol 0 +48hrs
Complete/partial suppression = Cushings disease
No suppression = ectopic source
39
Mx Cushings disease
Transphenoidal surgery
40
Def hypopituritism
Defective production of all pituitary hormones
41
PS hypopituritism
```
Fatigue
Myaglia
HoTN
Diabetes insipidis
Hypothyroidism
```
42
Pituitary causes of hypopituirism (3)
Obliteration - 1'/mets tumour
Surgical removal/irradiation
Ischaemic necrosis b/c HoTN shock
43
hypothalamic causes of hypopituiritism (4)
1' brain tumour = cranipharyngoma
Infarction
Sarcoid
Infection
44
Diagnosis hypopituritism
Pituitary hormones all low
Effector gland hormones = low
Low response to suppression tests
Imaging (to localise the pathology)
45
What is posterior pituitary disease usually a result of
Damage to hypothalamus (tumour invasion/infarction)
46
Failure of ADH prod -->
Diabetes insipidis
47
XS ADH production -->
SIADH
48
What is a pheochromocytoma
Catecholamine secreting tumour arising from sympathetic paraganglion cells (chromaffin cells)
49
What familial conditions are 10% of pheochromocytoma associated with?
Men 2a/b
NFM
Von Hippel-Lindau syndrome
50
PS pheochromocytoma
```
Severe HTN unresponsive to medical Sx
Sweating / heat intolerance
Visual disturbances/headaches
Seizures
Palpitation
Chest tightness
Dyspnoea
Postural hotn
Abdo pain
N+ C
```
51
What makes pt with pheochromocytoma Sx worse?
Stress
Exercise
Drugs
52
Which drugs must NOT be given alone to pt w/ pheochromocytoma
B-blockers
| due to LF HTN episodes
53
Diagnosispheochromocytoma
3x24h urine - raised free metadrenaline + normadrenaline
| CT/MRI - locate tumour
54
Mx pheochromocytoma (3)
Alpha block - phenoxybenzamine
B blockers once alpha established
Surgical excision
55
What is Addisons
Primary adrenal insufficiency due to destruction of adrenal cortex
56
How does Addisons differ from HPA disease?
HPA spares mineralcorticoid production (which = stim’d by ATII)
57
Most common cause Addisons UK
Autoimmune (80%)
58
Most common cause of Addisons worldwide
TB
59
Other causes Addisons
Overwhelming sepsis
Mets - lung/breast
Lymphoma
Waterhouse-Friderichsen syndrome
60
What is Waterhouse Friderichsen syndrome?
Adrenal gland failure because of bleeding into the adrenal glands
61
What is Waterhouse-Friderichsen syndrome most commonly caused ny
N.meningitides
62
Sx Addisons (3)
W loss/malaise/weakness/myalgia
Syncope
Depression
63
Signs Addisons (4)
Pigmentation esp on palmar creases + new scars
POstural HoTN
Signs dehydration
Loss body hair
64
Ix Addisons (6)
```
FBC
U+E
Ca
Glucose
Short ACTH stimulation/Synacthen test
9am cortisol/ACTH test
```
65
FBC results Addisons
Anaemia
66
U+E results Addisons
Low Na
High K
Uraemia
67
Ca2+ in Addisons
Raised
68
Glucose in Addisons
Low
| B/c lack of cortisol
69
Short ACTH stim test/Synacthen test (for Addisons)
Give tetracosactide IM (ACTH analogue)
measure plasma cortisol before + at 30mins after
2nd value >550nmol/L excludes Addisons
70
9am ACTH/Cortisol test Addisons
Raised ACTH
| Low/normal cortisol confirms Addisons
71
Ix for cause of Addisons (3)
21-hydroxylase adrenal antibodies - autoimmune disease
CXR for TB
Adrenal CT - look for TB/mets if antibodies negative
72
Mx Addisons (3)
LT glucocorticoid cover: 15-25mg HC daily in 3 divided doses
LT mineralocorticoid cover: fludrocortisone 50-200micrograms daily
Steroid card/Addisons bracelet _ IM HC in case of Addisonian crises
73
How should steroids be taken in Addisons + why
Avoid given late in day
| B/c can cause insomnia
74
When does LT mineralcorticoid cover need to be prescribed in Addisons (3)
If postural HoTN
If Low Na
If high K
75
When should extra doses of steroids be prescribed in Addisons?
If strenuous exercise
| Double for: surgery, febrile illness, trauma
76
Def Addisonian crisis
Severely inadequate levels of cortisol, occurring either as 1st PS of Adrenal disease or triggered by physiological events
77
PS Addisonian crisis (6)
```
Fever
N+V
Shock
Hypoglycaemia
Hyponatraemia
Hyperkalaemia
```
78
Mx Addisonian crises
IV Fl
| IV Hydrocortisone
79
What is CAH (Congenital adrenal hyperplasia)
Congenital deficiency in 21-alpha-hydroxylase
80
Role of 21-a-hydroxylase
Prod of mineralcorticoid s + glucocorticoids, but not sex hormones
81
CAH - levels of difference hormones
```
Aldosterone decreases
Cortisol decreases
ACTH hence rises
Precursors e.g. progesterone build up —> alt Sex hormone pathways
Hence testosterone increased
```
82
CF CAH in Females
Virilisation of external genitalia —> clitoral hypertrophy + variable fusion of labia
83
CF CAH in males
```
Enlarged penis
Pigmented scrotum
Salt losing crises 80% M at 1-3w age
Or
Non-salt losing M —> hypervirilisation - early pubarche, adult body odour, mom build
```
84
Ix CAH
17-a-hydroxyprogesterone levels MARKLY RAISED = diagnostic
85
Extra Ix for diagnosis CAH salt losers
Low Na
High K
Metabolic acidosis
86
Mx CAH
Steroid cover as per Addisons
87
What are CAH at risk of
Addisonian Crises
88
Who gets Conn’s syndrome?
Young females
89
What is COnns
Adrenal adenoma —> 1’ hyperaldosteronism
90
What are the 2 main causes of 1’ hyperaldosteronism
Conns (60%)
| Bilateral Adrenal hyperplasia (30%)
91
PS hyperaldosteronism (3)
Mostly asymp
To resistant HTN —> headache
Features of hypokalaemia —> cramps/weakness/tetany
92
Biochemical features Conns (2)
Hypokalaemia
| Elevated aldosterone: renin ratio
93
Ix Conns
Plasma Aldosterone levels NOT suppressed by fludrocortisone administration
Adrenal CT to differentiate COnns from adrenal hyperplasia
Adrenal scintigraphy - unilateral uptake in Conns
94
Mx COnns (2)
Laparoscopic adrenalectomy
| Spironolactone pre-op (control HTN/hypoK)
