Endocrinology Flashcards
What are the types of Thyroid cancer?
Which has best prognosis? Which has the worst?
Papillary: occurs in young patients
Follicular : common in women, over 50
Anaplastic: aggressive, often constricts airways
Medullary: Familial connection (MEN2), increased calcitonin levels
Best: Papillary Worst: Anaplastic
Most common type of thyroid cancer?
Classic features of it?
Papillary
- Psammoma bodies
- hypochromatic nuclei
What are MEN refer to? How many types?
MEN - multiple endocrine neoplasia
MEN 1, MEN 2A and MEN 2B
What conditions are associated with MEN 1? MEN 2A?
MEN1: the 3 P’s - Parathyroid, Pancreatic (& Pancreatic islet tumour) and Pituitary
MEN 2A: Phaechromocytoma, Parathyroid & Medullary thyroid cancer
Both are autosomal dominant inheritance
What is Phaeochromocytoma?
Presents as?
A tumour of the chromatin cells of the adrenal glands
Results in excess catecholamines (adrenaline)
Presents as: Resistant hypertension, severe headaches, anxiety, sweating, hyperglycaemia
Diagnostic test for Phaeochromocytoma?
Management?
Diagnosis: 24 urine catecholamines or serum metanephrines
Mx: Alpha blockers - phenoxybenzamine
Then add B blockers
Surgical removal is definitive management
What is Addisons Disease?
It occurs when there is adrenal insufficiency - resulting in lack of cortisol and aldosterone
Which blood test results will you see in Addisons?
Hyponatraemia & Hyperkalaemia & hypoglycaemia
Addisons = lack/no aldosterone and cortisol
Aldosterone acts to increase reabsorption of salt (Na) and water in kidneys to help increase blood pressure. Low levels of aldosterone means this does not occur and so there will be HYPOnatreamia
Potassium goes in the opposite direction to Na due to Na/K pump therefore there will be a HYPERkalaemia
Cortisol acts to promote gluconeogenesis by the liver to increased blood glucose. Low levels of cortisol means this won’t occur and so there will be a HYPOglycaemia
Addisons presents as?
Hypotension (can be postural) - no aldosterone
Pigmented skin (hyperpigmentation due to ACTH levels)
Fatigue,
Nausea
Cramps
Abdo pain
What is the diagnostic test for Addisons Disease?
Short Synacthen Test (stimulation test)
Give synacthen (synthetic ACTH) ideally in morning
then measure cortisol levels
Should double in normal patient by 30mins
Failure to double in this time - Addisons
Management for Addisons Disease?
Hydrocortisone (to replace lacking cortisol) and
Fludrocortisone (to replace lacking aldosterone)
What is hyperthyroidism? Types?
Hyperthyroidism is an excess of thyroid hormone production
Can be either:
Primary (pathology within thyroid gland)
or
Secondary (pathology before thyroid gland)
Give causes of hyperthyroidism. Explain each.
Grave’s disease - autoimmune condition where there are autoantibodies (TSH receptor stimulating antibodies) which mimic action of TSH
Toxic multi nodular goitre - nodules on the thyroid gland act independently of negative feedback and continue to produce excess T3 and T4
Thyroiditis - autoimmune condition of inflamed thyroid gland where thyroid tissue is destroyed and the stored T3 & T4 within the tissue is released resulting in high thyroid hormones
(eg. De quervains - presents with or just after viral infection - fever, neck pain, tenderness and dysphasia + hyperthyroid symptoms)
Presentation of Graves Disease?
Bilateral exophthalmos
Pretibial myxoedema
Anxiety, sweating, heat intolerance, weight loss, fatigue, menstrual irregularities such as oligomenorrhia
Management of hyperthyroidism
1) Carbimazole
2) Propylthiouracil
3) B blockers - Propanolol
Definitive management - Surgical removal
What is thyroid crisis or storm?
Mx?
Severe and often abrupt presentation of hyperthyroidism
Presents with: Fever, tachycardia, delirium + usual hyperthyroid symptoms
Mx - fluid resus, anti-arrythimics + propanolol + Carbimazole
In what condition is there excess growth hormone?
Acromegaly
What is the most common cause of Acromegaly?
Most common - Pituitary adenoma
Can be either macroscopic or microscopic
Macroscopic will see swelling and invading of the optic chiasm
How does Acromegaly present?
Prominent facial features: forehead and brow 'frontal bossing' Large hands and feet Large lower jaw Macroglossia Acanthosis ingrains of the axillae
What two other conditions are associated with Acromegaly?
Hypertension
Diabetes
How do you diagnose Acromegaly?
How do you manage it?
Diagnosis - IGF-1 level
- Oral glucose tolerance test
Management
- Transphenoidal surgery to remove pituitary adenoma
- Somatostatin analogue until surgery - Ocreotide
What is SIADH?
Syndrome of Inappropriate ADH
- where inappropriate excess ADH is secreted by either the pituitary or another source such as a paraneoplastic cancer - small cell lung cancer
What blood results do you see in SIADH?
As excessive ADH causes increased reabsorption of water - this dilutes the sodium circulating in the blood
Therefore there is hyponatraemia, and a high urine osmolality (more concentrated urine) and a low or normal serum/blood osmolality
What are the symptoms of SIADH?
Confusion
Headache, fatigue, muscle aches and cramps
Severe cases: seizures and reduced consciousness
What are the causes of SIADH?
Malignancy, particularly SMALL CELL LUNG CANCER
Infection, particularly atypical pneumonia and lung abscesses
Post-operative from major surgery
Head injury
Medications (thiazide diuretics, carbamazepine, vincristine, cyclophosphamide, antipsychotics, SSRIs, NSAIDSs,)
Meningitis
How do you diagnose SIADH?
Kind of a diagnosis of exclusion
Results: Euvolaemia. U+Es - hyponatraemia. Urine sodium and osmolality will be high
CXR is first line imaging to look for lung infection of cancer as source
Management of SIADH?
Treat cause
Fluid restriction - to try and balance out sodium level to normal
Demeclocycline can be used - inhibits ADH - rarely used in practice now though
What is hypothyroidism?
Inadequate production of thyroid hormones T3 and T4
Give examples of primary, secondary & tertiary hypothyroidism
Primary Hypothyroidism Hashimoto's Thyroiditis Iodine Thyroiditis As a result of over treatment of hyperthyroidism Meds such as lithium
Secondary Hypothyroidism
Pathology of the pituitary causing hypopituitarism (can be infection, tumour, vascular, radiation)
Tertiary Hypothyroidism
Failure of hypothalamus to respond to TRH and/or secrete TSH
What is Hashimoto’s thyroiditis?
Hashimoto’s Thyroiditis:
autoimmune of the thyroid gland and associated with anti-TPO antibodies & antithyroglobulin antibodies
Can initially cause a goitre but as it settles will cause atrophy of the thyroid gland
Typical symptoms and signs of hypothyroidism?
Fatigue, weight gain, dry skin, coarse hair & hair loss, irregular periods (menorrhagia), constipation
Diagnosis:
What do the following results indicate?
TSH - High, T3/T4 - Low
TSH - Low, T3/T4 - Low
TSH - High, T3/T4 - Low
- Primary hypothyroidism
TSH - Low, T3/T4 - Low
- Secondary hypothyroidism
(cause there should be a negative feedback loop and if T3/T4 is low then TSH should be high if higher centres are working properly)
Management for hypothyroidism?
Levothyroxine
What is a indication of severe pancreatitis?
Hypocalcaemia
