MIBG chromaffin seeking isotope scan - good for extraadrenal tumours
what is the treatment of phaeo?
pre-op: alpha (phenoxybenzamine) and beta block (alpha before beta to avoid crisis from unopposed alpha stimulation
post-op: do 24h urine catecholamines 2 wks post op, monitor BP as risk of very LOW
how is a phaeo emergency treated?
phentolamine: non selective alpha blocker to (vasodilates via alpha1)
or labetalol: mixed alpha and beta blocker
when BP controlled give phenoxybenzamine (alpha block)
also give B1 blocker e.g. atenolol/bisoprolol/metoprolol to control any tachycardia with phenoxybenzamine
then surgery after 6wks
what are the SE of phenoxybenzamine?
what is tabes dorsalis? and what causes it?
slow degeneration due to demyelination of nerves in dorsal column
caused by untreated syphilis
one of the symptoms is impotence
what is sick euthyroid syndrome?
but feel normal - asymp (due to adaptation?)
what is subclinical hypothyroidism?
when have symptoms but normal values
which cells does Medullary carcinoma of the thyroid arise from? what do they produce?
parafollicular C cells
what is the prognosis of follicular carcinoma?
50% if invasive get local recurrence or spread to bone/lung
what are the presenting features of primary ACUTE hypoadrenalism
what are the causes of primary ACUTE hypoadrenalism?
rapid withdrawal of long term steroid therapy
sepsis/stress in chronic adrenal dysfunction
perinatal haemorrhageic necrosis - after prolonged difficult labour because don't have many clotting factors likely to bleed
adrenal haemorrhage - heparin/warfarin/DIC
post partum infarction
warehouse friderichson syndrome: infection N.Meningitidis bacteraemia, low BP shock, DIC, bleed into adrenal gland
what are the clinical features of primary CHRONIC hypoadrenalism?
lethargy, depression, anorexia, wt loss
hypotension (low aldo)
hyperpigmentation: melanocytes stimulated by excess ACTH
what are the Na, K, urea, glucose levels in primary CHRONIC hypoadrenalism?
low glucose (as low cortisol)
what are the causes of primary CHRONIC hypoadrenalism?
autoimmune: destruction of cells = 80%
TB, mets, amyloid, haemochromatosis, lymphoma, AIDS = 20%
what are the causes of cushing's syndrome?
cushing's disease due to ACTH pituitary tumour,
ectopic ACTH (small cell lung cancer, carcinoid tumour) specific features due to LOTS of acth: hyperpigmentation, hypokalaemic met al (inc cortisol acts on MR), wt LOSS, hyperglycaemia. classical cushing's features may be absent.
iatrogenic - pharmacological doses of steroids (commonest)
adrenal adenoma or carcinoma
adrenal nodular hyperplasia
what are the first line screening tests for cushing's syndrome?
overnight dexamethasone suppression test. give dex at midnight and should cause -ve feedback, less ACTH and less cortisol at 8am
24h urinary free cortisol
when is cortisol highest and lowest and how can this be used as a test?
check cortisol at midnight, if raised its cushing's syndrome
how can you localise the lesion in cushing's syndrome i.e. pituitary/adrenal/ectopic?
1. measure plasma ACTH - if undetectable then ADRENAL tumour likely then CT the glands.
if ACTH is detectable then distinguish pituitary from ectopic ACTH production:
2. HIGH dose dex sup test: if cortisol levels are suppressed after 2days then its cushing's disease (i.e. pituitary cause) as pit retains SOME feedback
3. if not suppressed then it is ectopic ACTH - CT neck, thorax, abdomen for small cell lung cancer and carcinoid tumours
What is MODY?
maturity onset diabetes of the young
rare autosomal dominant form of DM2 affecting young people with a positive family history
what are the drug causes of DM?
what are the other causes of DM?
pancreatic: pancreatitis, surgery (removal of pancreas), haemochromatosis, cystic fibrosis, pancreastic cancer