Adrenal and Pituitary Disease Lecture Flashcards
What are the symptoms and signs that may make you suspect hypoadrenalism?
- Weight loss and lethargy
- Postural hypotension
- Nausea, vomiting
- Hyponatraemia +/- hyperkalaemia
- Addisonian crisis
What are some symptoms/signs of Addison’s Disease?
- Mucous membrane pigmentation
- Skin pigmentation (extensors, knuckles esp)
- Freckling
- Vertigo
- Pigment accentuation at nipples
- Pigment concentration in skin creases or scars
- Weight loss
- Anorexia
- Vomiting + diarrhoea
- Muscular weakness
- Postural hypotension
Why do you have changes to pigmentation in addison’s disease?
Increased ACTH causes increases melanocyte stimulating hormone
What are the clinical findings of an adrenal crisis?
- Dehydration, hypotension or shock out of proportion to illness
- N + V
- Weight loss
- Acute abdomen
- Unexplained hypogycaemia
- Unexplained fever
- Hyponatraemia, Hyperkalaemia, hypercalcaemia, eosinophilia, azotemia (urea + creatinine)
- Hyperpigmentation or vitiligo
- Other AI issues
What should low sodium and high potassium always make you think of?
Primary hyperadrenalism
What investigations should you do for hypoadrenalism?
Serum cortisol level: (random vs morning)
- Pulsatile secretion and diurnal variation makes interpretation difficult
- Time of day dependent
- Wide reference range (for morning cortisol level)
Stimulation testing:
- Short synacthen test (serum cortisol O’, 30’ and 60’ after synthetic ACTH 260 IM)
If patients are on exogenous glucocorticoids you can just diagnose clinically
How can you differentiate primary adrenal insufficiency from secondary or tertiary adrenal insufficiency?
The Synacthen Test/ACTH Stimulation Test
- ACTH should increase cortisol
If low cortisol = primary problem
Normal or increased cortisol= secondary or tertiary problem
Check plasma ACTH also
What other deficiencies should you investigate when you suspect PRIMARY adrenal insufficiency?
Mineralocorticoid deficiency!
- Hyperkalaemia
- Aldosterone and renin
What antibodies should you check for if someone has PRIMARY adrenal insufficiency?
Adrenal
Ovarian
Thyroid
How quickly can you withdraw glucocorticoids safely?
You can get clinically significant suppression after 2 weeks of glucocorticoids over supraphysiological doses
Reduce gradually!! Esp once at 7.5mg/day of pred
If someone with Addison’s disease is admitted with appendicitis- what should you consider in the management of them?
IMMEDIATE: the acute stress of the illness means they probs need more help
- IV hydration
- IV hydrocortisone 100mg
- When tolerating oral intake, commence on oral replacement and then taper down
LONG TERM:
- Need to be monitored to ensure replacement was enough
- Weight
- Cushingoid features
- Electrolytes
If someone presents with hypopituitarism presents with an acute illness what are your management priorities?
- Glucocorticoid assessment and replacement (IMPORTANT- this is life threatening so should be immediate)
- Then give thyroxine after
- Others (but not life threatening): gonadal hormones, growth hormone in children
What are the features of cushing’s syndrome?
- Depression/psychoses
- Mood alterations
- Cataracts
- Moon face
- Hirsutism
- HTN with secondary cardiomegaly
- Elevated glucose
- Muscle weakness
- Osteoporosis
- Thin skin
- Proximal myopathy
- Oligomenorrhea/amenorrhea
- Abdominal striae
What are some causes of Cushing’s?
ACTH Dependent Cushing’s Syndrome:
- Cushing disease
- Ectopic ACTH syndrome
- Ectopic CRH syndrome
ACTH Independent Cushing’s Syndrome:
- Adrenal adenoma
- Adrenal carcinoma
- Micro/Macronodular hyperplasia
Pseudo-Cushing’s Syndrome:
- MDD
- Alcoholism
How do you diagnose Cushing’s?
First:
- Increased urinary free cortisol (3 24hr collections)
- Lack of cortisol suppression after low-dose dexamethasone testing
- Increase Late evening salivary cortisol
Then: consider the ACTH vs not ACTH causes
- ACTH
- CRH test
- 8mg dex
- CT/MRI adrenal
- MRI pituitary
- BIPSS
What can cause false positives from the low dose dexamethasone suppression test (DST)?
- Increased oestrogen
- Decreased dexamethasone
- Drugs which increase hepatic metabolism of it: barbiturates, phenytoin
- Depression, alcoholism, chronic anxiety
What are some causes of secondary HTN?
- Renovascular disease
- Primary renal disease
- Oral contraceptives
- Phaeochromocytoma
- Cushing’s Syndrome
- Primary Aldosteronism
- OSA
- Coarctation of the aorta
- Hypothyroidism
- Primary hyperparathyroidism
What are some initial screening tests for the endocrine causes of secondary HTN?
Plasma metanephrines (fasting)
Aldosterone renin ratio:
- Hard to interpret if pt on anti-hypertensives
- Primary mineralocorticoid excess: renin suppressed, ratio up
- Secondary mineralocorticoid excess: renin increased (like renal artery stenosis), ratio down
Screening for hypercortisolism
What are some causes for a unilateral adrenal mass?
HORMONE EXCESS:
Adenoma
ACC
Pheochromocytoma
Adrenal hyperplasia
NO HORMONE EXCESS:
Adenoma
Myolipoma
Neuroblastoma
ACC
Metastasis
Cyst
What should you consider when investigating an adrenal mass?
SIZE:
- >3.5-4cm: may need surgery as difficult to exclude malignancy (can’t biopsy incase malignancy)
- Imaging can help as adenomas are lipid rich on imaging
HORMONAL ACTIVITY:
- Catecholamines important
What hormones are made by the adrenal gland?
What is the triad of phaeochromocytomas?
Headache
Sweating
Palpitations
How do you screen for a phaeochromocytoma?
Plasma metanephrines (fasting)
What are paragangliomas?
Extra-adrenal tumours
Genetic link with phaeochromocytoma
DDx of a large pituitary mass
BENIGN:
- Pituitary adenoma
- Meningioma
- Craniopharyngioma
PITUITARY HYPERPLASIA:
- Lactotroph hyperplasia (during pregnancy)
MALIGNANT:
- there’s a million I cbf typing
CYST
ABSCESS
What is the investigative approach to a pituitary mass?
- Assess and treat secondary hyperadrenalism (priority!!)
- Imaging: MRI is great
Biochemical:
- Pituitary hypofunction: secondary hypoadrenalism, hypothyroidism, hypogonadism
- Pituitary hyperfunction: prolactinoma, acromegaly, Cushing’s
Investigations for pituitary hypofunction:
Cortisol
T4
Male: testosterone, SHBG, FSH, LH
Female: oestradiol, progesterone, FSH, LH
What is pituitary hormonal replacement?
Glucocorticoid:
- Hydrocortisone
Thyroxine
Gonadal hormones:
- Testosterone
- Oestrogen
Growth hormone
ADH/Vasopressin
What can hyperprolactinaemia do?
Cause hypogonadotrophic hypogonadism
What causes hyperprolactinaemia?
- Prolactin secreting adenoma (prolactinoma)
- Dopamine antagonism (metoclopramide, anti-depressants)
- Renal failure
- Pregnancy
What are some symptoms/complications of prolactinomas?
Mass effect: headaches, visual field defect (bitemporal hemianopia)
Hypopituitarism
What are prolactinomas really sensitive to?
Dopamine agonists so might not even need surgery
