Endocrine 2 Flashcards
definition of hypoparathyroidism
Relative or absolute deficiency of plasma parathyroid hormone (PTH) synthesis and secretion.
what are the biochemical changes in hypoparathyroidism?
low Ca2+
high phosphate
aetiology of hypoparathyroidism?
mainly due to surgical management of thyroid disease
thyroid surgery
parathyroidectomy
hypomagnesemia - severe low level leads to inhibition of PTH secretion
autosomal dominant conditions
autoimmune body resistance to PTH
clinical symptoms of hypoparathyroidism
asymptomatic chronic alcoholism malnutrition, malabsoption, diarrhoea muscle twitches, spasm, cramps - tetany paraesthesia, numbness, tingling poor memory slowed thinking anxiety dry hair, brittle nail cataracts • Cheotveks sign- twitching of facial muscles on tapping facial nerve • Trousseau sign-carpopedal spasm caused by inflating the blood-pressure cuff to a level above systolic pressure for 3 minutes
what is the acronym used for hypoparathyroidism
PTH
P - parathesis, positive Chetoveks & positive trousseau
T- tetany (muscle cramping and consultation)
H - hypocalcemia
differentials for hypoparathyroidism
low vit D hypomagnesaemia hypoalbuminemia pesudohypoparathyroidim renal failure, CKD
investigation and management of hypoparathyroidism
- Refer to endocrinology
- Bloods: serum calcium (low), serum albumin (normal, if low can give falsely low serum calcium level), PTH, magnesium (may be low), serum 25-hydroxyvitamin D ( low), serum phosphorus (elevated), UE.
- ECG (prolonged QT)
• Oral calcium, Vitamin D, PTH injection
what are the different types of thyroid cancer
papillary follicular medullary anaplastic - these 4 types of cancer make up 98% of thyroid cancer
other -
thyroid lymphoma
hurthe cell carcinoma
aetiology of thyroid cancer
ionising radiation Hx of goitre thyroid nodule thyroiditis Fhx of thyroid disease female Asian
symptoms of thyroid cancer
thyroid nodule - hard and fixed, non-tender, rapid growth
hoarse voice - involvement of the recurrent laryngeal nerve
stridor - involvement of the airway
cervical lymphadenopathy
differentials for thyroid cancer
benign thyroid nodule
what are the investigations and management for thyroid cancer
- Two-week referral pathway or same day referral if thyroid lump and stridor.
- Bloods: TFT (normal), serum calcitonin (made by the thyroid and is a good tumour marker)
- US, fine needle biopsy
- I-123 thyroid scan and uptake – hot nodule = rule out
- Rx: surgery, radioiodine ablation, RT.
definition of multi-nodular goitre
Multiple autonomously functioning nodules, resulting in hyperthyroidism. These nodules function independently of thyroid-stimulating hormone and are almost always benign
aetiology of mutli-nodular goitre
Most hyperfunctioning nodules have thyroid cell germline mutations that affect the thyroid-stimulating hormone (TSH) receptor.
RF - iodine deficiency, head and neck irradiation, > 40 years, female
clinical features of multi-nodular goitre
goitre - irrgular and rapidly growing
palpable multiple thyroid nodules
symptoms of hyperthyroidism
differential for multi-nodular goitre
-Grave’s Disease
-toxic adenoma
-thyrotoxic phase of painless/lymphocytic thyroiditis
-iodine-induced
hyperthyroidism
what are the investigation and management of multiple nodular goitre
- Refer to endocrinology
- Bloods: TSH, T3/T4, iodine thyroid scan and uptake, Tc-99 pertechnetate scan, thyroid ultrasound, TSH receptor antibodies, thyroid peroxidase antibodies.
• Rx: radioactive iodine therapy, antithyroid drugs, thyroid surgery, b-blockers
what are the causes of toxic nodules
thyroid adenoma (autonomously functioning thyroid nodule that causes hyperthyroidism)
cyst
cancerous tumour
aetiology of toxic goitre
arises after activating (gain of function) germline mutations in thyroid cells
RF for toxic goitre
iodine deficiency 20-40 yrs female head and neck irradiation FHx
clinical symptoms of toxic goitre
palpable single thyroid nodule
symptoms of hyperthyroidism
investigation and management of toxic goitre
TSH, T3/T4, TSH receptor antibodies
thyroid peroxidase antibodies
thyroid US, thyroid scan and uptake
radioactive iodine therapy, antithyroid, thyroidectomy, beta-blocker
what is a simple goitre
enlarged thyroid gland
can lead to euthyroid, hyperthyroidism, hypothyroidism
aetiology for a simple goitre
Graves
Hashimoto’s thyroiditis
radiotherapy
iodine deficiency
drug (lithium and amiodarone)
clinical symptoms of a simple goitre
asymptomatic except swelling in neck
can be painless or painful (uncommon)
symptoms of either hyperthyroidism or hypothyroidism
difficulty breathing and swallowing as goire presses on the airway and the oesophagus
investigation and treatment for a simple goitre
refer to endocrinology
bloods - TSH, T3/T4, iodine thyroid scan, Tc-99 pertechnetate scan, thyroid USS
Tx - depends on cause, radioactive iodine (if hyperthyroidism), thyroidectomy (if cancer), iodine replacement (thyroxine if hypothyroidism)
definition of thyroiditis
swelling (inflammation) of the thyroid gland which can result in hyper or hypothyroidism
what are the different types of thyroiditis
Hashimoto - hypothyroidism
De Quervain’s (subacute thyroiditis. Painful swelling of the thyroid gland triggered by a viral infection)
post-partum thyroiditis - autoimmune hyperthyroidism 6 months after giving birth
silent thyroiditis
Drug-induced - amiodarone, and lithium
radiation-induced
acute or infectious thyroiditis - triggered by a bacterial infection and associated with a weakened immune system
what are the clinical symptoms of De Quervain’s thyroiditis
fever
pain in the neck, jaw, and ear
initially - hyperthyroidism (a few days)
followed by hypothyroidism (lasting weeks or months)
return to normal thyroid infection
what are the clinical symptoms of Post-partum thyroiditis?
6 months since delivery
initially - hyperthyroidism (a few days)
followed by hypothyroidism (lasting weeks or months)
return to normal thyroid function by 12-18 months
what are the clinical symptoms of silent thyroiditis?
painless
initially - hyperthyroidism (few days)
followed by hypothyroidism (lasting weeks or months)
what are the clinical symptoms of drug-induced thyroiditis?
symptoms short-lived and cease upon stopping medication
what are the clinical symptoms of radiation-induced thyroiditis?
either symptom of over or underactive thyroid
what are the clinical symptoms of acute or infectious thyroiditis?
pain in the throat, feeling generally unwell, swelling of the thyroid glands
symptoms of underactive/overactive thryoid glands
investigations and treatment
• Refer to endocrinology or treat in PC if possible.
• blood - TSH, T3/T4, CRP
Tx: depends on cause
definition of hypopituitarism
partial or complete deficiency of one or more pituitary hormones
what are the hormones which are secreted in the anterior pituitary glands
growth hormone prolactin LH FSH ACTH TSH
what are the hormones which are secreted in the posterior pituitary glands
vasopressin
oxytocin
aetiology of hypopituitarism
Neoplastic - pituitary adenoma - most common cause of hypopituitarism
vascular - Sheehan’s, intrasellar aneurysm, pituitary apoplexy
inflammation and infiltrative lesion - lymphocytic hypophysis, hemochromatosis, sarcoidosis
infection - pituitary abscess, pituitary tuberculomas, fungal pituitary disease
congenital
RT
pituitary surgery
what is the most common cause of hypopituitarism
pituitary adenoma
clinical features of hypopituitarism
headaches FFT infertility hypoglycaemia amenorrhoea/oligomenorrhoea glatactorrhoea delayed puberty visual field defects/opthalmooplegia CVD cold intolerance weight gain, N+V, constipation fatigue
investigation for hypopituitarism
- Refer to endocrinology
- Bloods: all hormones secreted by the pituitary gland
- Rx: depends on the cause.
definition of pituitary tumors
tumor of the pituitary gland which is most commonly benign
what is a RF associated with pituitary tumours
MEN 1
what are the different types of pituitary tumours
non-functioning adenoma - reduced symptoms by pressure on surrounding structures
prolactinomas
growth hormone-secreting
adrenocorticotrophic hormone-secreting
Thyroid-stimulating hormone secreting
LH/FSH-secreting tumours
clinical features of pituitary tumours
depends on the hormone secreted by the tumours as well as the pattern of growth of the tumour within the sell turcica
local effects resulting from a pituitary mass
- headache, neuro-ophthalmologic defect (bitemporal hemianopia), extensive extension into the hypothalamus
anterior pituitary deficiency
- occurs in the following order, LH, GH, TSH, ACTH, FSH
- infertility, oligo/amenorrhoea, dec libido, erectile dysfunction, dec muscle bulk, dec body hair, central obesity, small testes
- in children - delayed or stunned growth
- diabetes inspidius
hypersecretion
- acromegaly, hyperprolactinaemia, Cushing’s Disease, thyrotoxicosis
investigation and treatment
- Refer to endocrinology.
- Pituitary function screen: GnRH, LHRH, TRH, ACTH, growth hormone, insulin tolerance test.
- MRI.
- Rx: depends on cause e.g. bromocriptine for prolactin-secreting tumors.
which hormone proves to be a -ve feedback to HPA axis
cortisol
what are the hormones released in the HPA axis
hypothalamus - corticotrophin-releasing hormone to stimulate anterior pituitary gland
anterior pituitary - releases adrenocorticotropic hormone to stimulate the adrenal cortex
adrenal cortex releases cortisol which act as -ve feedback for anterior pituitary gland and hypothalamus
what is the main cause of HPA axis suppression?
excess glucocorticoids in the system, cortisol = glucocorticoids
what is the overall consequence of HPA axis suppression?
dec production of both corticotropin-releasing hormone from the hypothalamus and adrenocorticotropic hormone from the pituitary glands –> dec in serum cortisol levels
what are some of the causes of HPA axis suppression
exogenous glucocorticoids - most common cause
- sudden cessation or rapid tapering of glucocorticoids
- common in conditions like asthma and COPD
- megestrol use
clinical features of HPA suppression
Hx of weight gain and inc appetite
Hx depression, agitation or sleep disorders
Hx of easy bruising
fatigues, anorexia or weight loss
N+V
dizziness or orthostatic symptoms
mylagia or arthralgia
abdo pain
cushingoid features - moon faces, facial plethora, dorsocervical fat pad, bruising, violaceous abdo striae, thin skin, proximal muscle weakness and centripetal obesity
Hx of difficult to control diabetes or hypertension
differentials for HPA suppression
primary adrenal insufficiency
pituitary compression, tumour, head trauma and surgery (non-Cushing)
corticosteroids withdrawal
investigation and management of HPA suppression
refer to endocrinology
ix - serum cortisol (low), synathecen test (rise in cortisol > double, excludes adreneal insufficiency)
treatment - steriods
what is pheochromcytoma
Benign or malignant tumour of adrenal gland which results in the release of too much epinephrine and norepinephrine.
RF for pheochromocytoma
- FHx
- MEN type 2
- Von Hippel-Lindau syndrome
- neurofibromatosis type 1
- germ-line mutations in succinate dehydrogenase (SDH) - B, -C or _D genes
clinical features of pheochromocytoma
classic triad - palpitations, headache, diaphoresis
- Episodic spells of symptoms which vary in duration and get worse as time goes on
- Young age onset hypertension
- Resistant intractable hypertension.
differentials for pheochromocytoma
-anxiety and panic attacks
- essential or intractable hypertension
- illict drugs
- carcinodi syndrome
cardiac arrythemias
menopause
pre-eclampsia
investigation for pheochromocytoma
Ix
- 24 hours urine collection for catecholamine, metanephrines, normetanephrines - creatines
- plasma catecholamines
- genetics testing
Treatment for pheochromocytoma
antihypertensives
alpha blockers
beta blockers
surgery
definition of Cushing’s Syndrome
signs and symptoms that develop after prolonged abnormal elevation of cortisol
definition of Cushing’s Disease
refer to specific condition where a pituitary adenoma secretes excessive ACTH
aetiology of Cushing’s Syndrome
- exogenous steroid
- adrenal adenoma
- paraneoplastic cushing’s - excess ACTH from cancer eg SCLC
clinical features of Cushing’s Syndrome
round in the top and middle with thin limbs
- moon face
- central obesity
- abdo striae
- buffalo hump (fat pad)
- proximal limb muscle wasting
high level of stress hormone
- hypertension
- cardiac hypertrophy
- T2DM
- depression
- insomnia
- oesteoporosis
- easy bruising and poor skin healing
investigation and treatment of Cushing’s syndrome
Dexamethasone suppression test - given at 10 pm at night and measure at 9am
if at low dose test - high/normal cortisol level –> then Cushing’s syndrome
MRI
treatment - surgery
pathophysiology of adrenogenital syndrome
aka congenital adrenal hyperplasia
- Deficiency of 21-hydroxylase = required for cortisol (stress response) and aldosterone (blood pressure and Na+ and K+) synthesis
- Low cortisol increases ACTH = adrenal hyperplasia and increased synthesis of androgen
• Unable to produce aldosterone = salt loss.
- causing the development of male features in females and early puberty in both boys and girls
what is the genetic patterns of adrenogenital syndrome?
autosomal recessive
what are the clinical features of adrenogenital syndrome
female virilisation (inc muscle bulk etc), clitoral hypertrophy and fusion of labia (ambiguous genitalia)
male have enlarged penis and pigmented scrotum
salt losing adrenal crisis - vomiting, weight loss, hypotonia, circulatory collapse
non-salt losers - tall statures, muscle bulk, precocious pubarche, acne, pubic hair
investigation for adrenogenital syndrome
RAISED 17 A hydroxy-progesterone
urine and blood steroids (low)
hyponatraemia, hyperkalaemia, hypoglycaemia
treatment for adrenogenital syndrome
Female- corrective and constructive surgery
Salt losing crisis – sodium chloride, glucose and hydrocortisone IV.
1)Long-term
Life long glucocorticoids (hydrocortisone)
Mineral corticoids (for salt loss) (mineral cortisone)
Monitor growth, skeletal maturity and plasma androgens and 17 a hydroxy progesterone
Illness- IM cortisol
what is the job of aldosterone?
regular blood pressure, blood volume, level of NA+, K+ and H+ through the RAA system
what is Conn’s syndrome
primary hyperaldoseteronism
- when adrenal glands are directly responsible for producing too much aldosterone
- serum renin will be low as it is suppressed by the high BP
aetiology of Conn’s syndrome
- adrenal adenoma secreting aldosterone (most common)
- bilateral adrenal hyperplasia
- familial hyperaldosteronism type 1 and type 2 - rare
- adrenal carcinoma (rare)
what is secondary hyperaldosteronism
excessive renin stimulating the adrenal glands to produce more aldosterone
aetiology of secondary hyperaldosteronism
- serum renin will be high
- renal artery stenosis
- renal artery obstruction
- heart failure
clinical features of hyperaldosteronsims
high BP fatigue headache vision problems muscle weakness - caused by hypokalemia numbness temporary paralysis inc urination inc thrist
investigation for hyperaldosteronism
investigation
- renin/aldosterone ration (high aldoseterone + low renin = primary), (high aldosterone + high renin = secondary)
- BP
- U&E (hypokalaemia, hypernatreamia)
- ABG (alkalosis) due to excretion of H+ ion
Treatment
- aldosteron antagonist –> eplerenone, spironolactone, surgery, percutaneous angioplasty for renal artery stenosis
