Extra endocrine Flashcards
What is a phaeochromocytoma
Catecholamine producing tumour
Where do you phaeochromocytomas
Usually arises from chromaffin cells of adrenal medulla (10% are bilateral and 10% are malignant)
Or can be non-adrenal in origin - in which case called paragangliomas
Cause of phaeochromocytoma
Sporadic cases, cause unknown
Familial in up to 30% - including MEN2a, neurofibromatosis type 1, von-hippel-lindau, and mutations in subunits of mitrochondrial enzyme succinate dehydrogenase (SDHB, SDHC, SDHD)
Features of phaeochromocytoma
Paroxysmal episodes of sweating, headache
Palpitations, chest pain, dyspnoea
Epigastric pain, nausea and constipation
Weakness, tremor and anxiety
Hypertension - 2/3 sustained 1/3 paroxysmal
Pallor tachycardia, fever and weight loss
Investigations for phaeochromocytoma
24hr urine to look for urinary catecholamines (adr, NA, dopamine)
CT or MRI for tumour identification
123I-MIBG scintigraphy to look for malignancy
Screen for associated conditions
Bloods in phaeochromocytoma
calcium may be elevated, hypokalaemia
What drugs can increase measured catecholamines
TCA’s
Levodopa
Medical treatment of phaeochromocytoma
rehydrate first
alpha blockade with phenoxybenzamine
b-blockade with propanolol (2 days after alpha blockade)
Surgical management of phaeochromocytoma
Adrenalectomy
Chemotherapy and surgery if mets
Follow up for phaeochromocytoma
Lifelong follow up because of recurrence
What is carcinoid syndrome
Constellation of symptoms caused by systemic release of humoral factors (including biogenic amines, polypeptides, prostaglandins eg. serotonin, histamine, tachykinins, kallikrein ) from carcinoid tumours
What are carcinoid tumours?
Slow-growing neuroendocrine tumours mostly derived from serotonin-producing enterochromaffin cells
Where are majority of carcinoid syndrome producing tumours
In small bowel
Common sites include appendix and rectum but these are often benign and non-secretory
When do symptoms of carcinoid syndrome present?
Hormones released into portal circulation are metabolised in liver therefore usually don’t get symptoms until mets have spread to liver and then get products in hepatic vein
Signs + symptoms of carcinoid tumour
Paroxysmal flushing, diarrhoea, crampy abdo pain, wheeze, sweating and palpitations
Facial flushing, telangiectasia
Tricuspid stenosis, regurge or pulmonary stenosis
What are symptoms of carcinoid crisis
Profound flushing, bronchospasm, tachycardia and fluctuating blood pressure
Investigations in carcinoid syndrome
24h urine collection for 5-HIAA levels (metabolite of serotonin)
Blood for plasma chromogranin A and B - fasting gut hormones
Radioisotope scan with radiolabelled somatostatin analogue helps localise tumour
Management of carcinoid crisis
Octreotide infusion, IV antihistamine and hydrocortisone
Treatment of carcinoid syndrome
Octreotide (somatostatin analogue inhibits hormone release and tumour growth) radiolabelled may be beneficial
Interferon-alpha if octreotide is not enough
When consider surgery for carcinoid syndrome
For resectable nodal or hepatic mets or tumours
Valve surgery for symptomatic carcinoid heart disease
What is men 1?
Also called Wermer syndrome Pancreatic tumours Pituitary adenomas Parathyroid hyperplasia Angiofibroma (vascular lesion at back of nasal cavity) Lipoma
What is Men 2a
Medullary thyroid carcinoma
Phaeochromocytoma
Parathyroid hyperplasia
What is Men 2b
Medullary thyroid carcinoma
Phaeochromocytoma
Marfanoid body habitus
Mucosal neuroma (lumps on mucosal surfaces eg. lips and tongue)
Management of acute severe hypercalcaemia
Fluid resus
Bisphosphonates - IV pamidronate - takes a few days to work
Serum level required for hypercalcaemia
2.65 or higher
Common causes of hypercalcaemia
HyperPTH
Cancer
What is MODY
Maturity onset diabetes of the young - onset of diabetes t2 in under 25yr old
Features of MODY
Autosomal dominant with strong family history
Doesn’t usually present with ketosis
Normally very sensitive to sulphonylureas
Test to tell between T1DM and T2DM
C-peptide - decreased in T1DM
Raised or normal in T2dm
Type of goitre in hashimotos
non-tender goitre
Goitre in de quevains thyroidistis
painful
Thyroid bruit + hyperthyroid?
Graves
