Endocrine Flashcards
What is acromegaly and what are the causes?
In acromegaly there is excess growth hormone secondary to a pituitary adenoidal in over 95% of cases. A minority of cases are caused by ectopic GHRH or GH production by tumours.
What are the features of acromegaly?
Coarse facial appearance, spade like hands, increase in shoe size
Large tongue, prognathism, interdental spaces
Excessive sweating and oily skin
Features of pituitary tumour (hypopituitarism, headaches, bitemporal hemianopia)
Raised prolactin
6% patients have MEN-1
What are the complications of acromegaly?
Hypertension Diabetes Cardiomyopathy Colorectal cancer Pseudogout
What are the investigations of acromegaly?
Insulin-like-growth-factor 1 (IGF-1) is the initial screening test (raised)
Oral glucose tolerance test (glucose normally suppresses growth hormone)
MRI brain for pituitary tumour
What are the treatments for acromegaly?
Trans-sphenoidal surgery for pituitary tumour
Medications that block growth hormone:
- Pegvisomant
- Somatostatin analogues
- Dopamine agonists
What is De Quervain’s thyroiditis?
Subacute thyroiditis is thought to occur following viral infection and typically presents with hyperthyroidism
What are the four phases of de quervain’s thyroiditis?
- Hyperthyroidism, painful goitre, raised ESR
- Euthyroid
- Hypothyroidism
- Thyroid structure and function back to normal
What is the investigation for De quervain’s thyroiditis?
Thyroid scintigraphy: globally reduced uptake of iodine-131
What is the management of de quervain’s thyroiditis?
Usually self-limiting
Aspirin or other NSAIDs for pain
Maybe steroids if severe
What is the difference between the different types of multiple endocrine neoplasia (MEN)?
MEN I: Parathyroid, Pituitary, Pancreas (also adrenal and thyroid)
MEN II: Parathyroid, Phaeochromocytoma
MEN III: Phaeochromocytoma
What is the difference between Cushing’s syndrome and Cushing’s disease?
Cushing’s syndrome is used to refer to the signs and symptoms that develop after prolonged abnormal elevation of cortisol.
Cushing’s disease is used to refer to the specific condition where a pituitary adenoma secretes excessive ACTH.
Cushing’s disease causes a Cushing’s syndrome but not all Cushing’s syndrome is caused by Cushing’s disease.
What are the features of Cushing’s syndrome?
Round in the middle with thin limbs:
Round moon face
Central obesity
Proximal limb muscle wasting
High levels of stress hormone: Hypertension Cardiac hypertrophy T2DM Depression
What causes Cushing’s syndrome?
Exogenous steroids
Cushing’s disease
Adrenal adenoma
Paraneoplastic Cushing’s
How is the dexamethasone suppression test used in Cushing’s syndrome?
Low dose (1mg): Low cortisol = normal High/normal cortisol = Cushing’s syndrome
High dose (8mg) to find out the cause: Low cortisol = Cushing’s disease (pituitary adenoma) High/normal cortisol + ACTH low = adrenal Cushing’s High/normal cortisol + ACTH high = ectopic ACTH
What are some other investigations of Cushing’s syndrome other than the dexamethasone suppression test?
24 hour urinary free cortisol FBC MRI brain for pituitary adenoma Chest CT for small cell lung cancer Abdominal CT for adrenal tumours
What is the treatment for Cushing’s syndrome?
Trans-sphenoid also removal of pituitary adenoma
Surgical removal of adrenal tumour
Surgical removal of tumour producing ectopic ACTH
What is Addison’s disease?
Refers to a specific condition where the adrenal glands have been damaged, resulting in reduced secretion of cortisol and aldosterone.
Also called primary adrenal insufficiency
What is the cause of Addison’s disease?
Most common cause is autoimmune
What are the features of Addison’s disease?
Lethargy, weakness, anorexia, N+V, weight-loss
Bronze Hyperpigmentation (especially palmer creases)
Hyponatraemia and hyperkalaemia
What is the investigation for Addison’s disease?
Definitive: ACTH stimulation test (short Synacthen test)
Synthetic ACTH (Synacthen) is given and blood cortisol is measured at baseline, 30 mins and 60 mins. In healthy people, the adrenal glands should produce at least double cortisol in response to synacthen. Failure of cortisol to rise indicates Addison’s
U+E (hyponatraemia and hyperkalaemia) Blood glucose (Hypoglycaemia) Low cortisol Low aldosterone High renin High ACTH
What is the management of Addison’s disease?
Hydrocortisone and fludrocortisone hormones are used to replace cortisol and aldosterone respectively.
IV hydrocortisone in addisonian crisis
What are the sick day rules for Addison’s disease?
Dose of steroid increased
Blood sugar monitored
IM injection of steroid for D+V
What are the different types of hyperthyroidism?
Primary: due to thyroid itself producing excessive thyroid hormones. E.g. Graves is due to an autoimmune condition where TSH receptor antibodies are produced - they mimic TSH.
Secondary: where there is excessive TSH due to pathology in hypothalamus or pituitary
Toxic multinodular goitre: where nodules develop on the thyroid gland that act independently of the normal feedback system and continuously produce excessive thyroid hormone
What are the causes of hyperthyroidism?
Grave’s disease
Toxic multinodular goitre
Solitary toxic thyroid nodule
Thyroiditis (e.g. de quervain’s, hashimotos)
What are the unique features of grave’s disease?
Diffuse goitre (without nodule)
Grave’s eye disease
Bilateral exopthalmos
Pretibial myxoedema
What are the unique features of toxic multinodular goitre?
Goitre with firm nodules
Most patients are over 50
Second most common cause of thyrotoxicosis after graves
What is the management of hyperthyroidism?
Carbimazole: First line
Complete remission and the ability to stop taking carbimazole is usually achieved within 18 months of treatment
Propylthiouracil: Second-line
Radioactive iodine
Beta blockers
Surgery: definitive treatment
Will need levothyroxine afterwards
What are the causes of hypothyroidism?
Hashimoto’s thyroiditis:
- associated with anti-TPO antibodies and antithyroglobulin antibodies
- most common in developed world
Iodine deficiency
- most common in developing world
Secondary to hyperthyroidism treatment
Medications:
Lithium or amiodrone
Secondary hypothyroidism causes:
- tumours, infection, vascular, radiation
What are the presentation and features of hypothyroidism?
Weight gain Fatigue Dry skin Coarse hair and hair loss Fluid retention Heavy or irregular periods Constipation
What are the investigations for hypothyroidism?
Primary: High TSH and low T3/4
Secondary: Low TSH and low T3/4
What is the management of hypothyroidism?
Oral levothyroxine.
Measure TSH levels monthly until stable.
What is type 1 diabetes mellitus?
Where the pancreas stops being able to produce insulin.