Week 11 - Endocrine Flashcards
what is onycholysis?
painless detatchment of nail from nailbed
in what endocrine disorder is lid retraction seen? and why?
hypertyroidism e.g. Graves Disease
sympathetic hyperactivity causing excessive contraction of the superior tarsal and levator palperbrae superioris muscles
what is exophtalmos?
bulging of the eye
graves disease
what is lid lag and what is it most commonly associated with?
delay in the descent of the upper eyelid in relation to the eyeball when looking downward
Graves
what happens to thyroid gland masses, lymph nodes and invasive thyroid malignancies during swallowing?
- Thyroid gland masses will move upward with swallowing.
- Lymph nodes will not move much during swallow
Invasive thyroid malignancy may not move with swallow
- Lymph nodes will not move much during swallow
what will move up upon tongue protrusion in the thyroid?
thyroglossal cysts
what happens to thyroglossal cysts on tongue protrusion?
moves upwards
what will not move in the thyroid with tongue protrusion?
thyroid gland masses
lymph nodes
what happens to thyroid gland masses and lymph nodes on tongue protrusion?
will not move
what does dullness on percussion of the sternum in a thyroid exam indicate?
large thyroid mass that extends posterioinferiorly to the sternum
how many parathyroid glands are there and where are they located?
4
small and on posterior surface of thyroid gland
what is the structure of the thyroid?
2 lateral lobes → cover the anterolateral surfaces of the trachea, cricoid cartilage and lower part of thyroid cartilage
Isthmus → connects lateral lobes. Crosses anterior surfaces of 2nd and 3rd tracheal cartilages
what is the arterial supply to the thyroid?
superior and inferior thyroid arteries
what is the arterial supply to the parathyroid glands?
○ Inferior thyroid arteries
Superior thyroid arteries may contribute to supply of superior parathyroid glands
what is the main function of the thyroid?
- Main regulator of metabolism
- TH3/TH4 act via nuclear receptors in target tissues and initiate a variety of metabolic pathways.
- Metabolic pathways include →
○ Basal metabolic rate
○ Gluconeogenesis
○ Glycogenolysis
○ Protein synthesis
○ Lipogenesis
○ Thermogenesis - Achieve in ways such as →
○ Increasing size & number of mitochondria within cells
○ Increasing Na-K pump activity
Increasing the presence of β-adrenergic receptors in tissues such as cardiac muscle
what is released in detection of low plasma conc of thyroid hormone?
hypothalamus detects it and releases thyrotopin-releasing hormone
TRH
what is the action of TRH?
binds to receptors on thyrotrophic cells of the anterior pituitary gland which causes release of TSH
where is TSH released from?
anterior pituitary gland
which cells synthesise and release thyroid hormone?
thyroid follicular cells
which structures are able to convert T4 to T3?
○ Liver
○ Kidney
○ Muscle
○ Thyroid
○ Pituitary gland
○ Brown adipose tissue
Central nervous system
which of T4 and T3 is inactive?
T4
what is the function of T3/T4?
○ Regulating the metabolic rate
○ Slowing down or speeding up heart rate
○ Raising or lowering body temperature
○ Influencing the speed at which food moves through digestive tract
○ Affecting brain development
○ Controlling the way your muscles contract
○ Managing skin and bone maintenance by controlling rate at which your body replaces dying cells
how are thyroid hormones found in the circultataion (in what state)?
bound to transport proteins
they are lipophillic
what is the location of pathology in primary and secondary hyperthyroidism?
primary = thyroid pathology
secondary = pathology of hypothalamus or pituitary
what is graves disease?
autoimmune condition where TSH receptor antibodies cause primary hyperthyroidism. These TSH receptor antibodies, produced by the immune system, stimulate TSH receptors on the thyroid. This is the most common cause of hyperthyroidism.
what is the most common cause of hyperthyroidism?
Graves
what is toxic moltinodular goitre?
condition where nodules develop on the thyroid gland, which are unregulated by the thyroid axis and continuously produce excessive thyroid hormones. It is most common in patients over 50 years.
what is hypothyroidism?
insufficient thyroid hormones, triiodothyronine (T3) and thyroxine (T4).
what is primary hypothyroidism?
thyroid behaves abnormally and produces inadequate thyroid hormones. Negative feedback is absent, resulting in increased production of TSH. TSH is raised, and T3 and T4 are low.
what is secondary hypothyroidism?
where the pituitary behaves abnormally and produces inadequate TSH, resulting in under-stimulation of the thyroid gland and insufficient thyroid hormones. TSH, T3 and T4 will all be low.
patient has low TSH and high T3/T4. what is this?
primary hyperthyroidism
a patient has high TSH and high T3/T4. what is this?
secondary hyperthyroidism
a patient has high TSH and low T3/T4. what is this?
primary hypothyroidism
a patient has low TSH and low T3/T4. what is this?
secondary hypothyroidism
where is TRH released?
hypothalamus
where does TRH act upon?
anterior pituitary
where does TSH act upon?
thyroid
how are radioisotope scans used in thyroid disorders?
investigate hyperthyroidism and thyroid cancers
○ Radioactive iodine is given orally or IV and travels to thyroid, where it’s taken up by thyroid cells. Iodine needed to produce thyroid hormones.
○ Gamma camera detects gamma rays emitted from radioactive iodine, the greater the rays emitted, the more radioactive iodine has been taken up:
diffuse high uptake of radioactive iodine is seen in a radioisotope scan. what does this suggest?
graves
what would be seen in a radioisotope scan of someone with graves disease?
diffuse high uptake
focal high uptake of radioactive iodine is seen in a radioisotope scan. what does this suggest?
toxic multinodular goitre and adenomas
what is seen on a radioisotope scan in toxic multinodular goitres and adenomas?
focal high uptake
cold area e.g. abnormally low uptake of radioactive iodine is seen in a radioisotope scan. what does this suggest?
thyroid cancer
what is seen on a radioisotope scan in thyroid cancer?
cold area
abnormally low uptake
when are anti-TPO antibodies present?
antibodies against thyroid gland – most relevant thyroid autoantibody in autoimmune thyroid disease.
Present in Grave’s disease and Hashimoto’s thyroiditis
when are anti-Tg antibodies seen?
antibodies against thyroglobulin – protein produced and present in thyroid gland.
Raised in Grave’s, Hashimoto’s and thyroid cancer.
Can be present in healthy individuals too.
when are TSH receptor antibodies seen?
autoantibodies that mimic TSH. Bind to TSH receptor and stimulate thyroid hormone release.
Cause Grave’s disease
what medication is often used to treat hyperthyriodism?
carbimazole
what is carbimazole used in?
hyperthyroidism
what are the contraindications to carbimazole?
severe blood disorders
what side effects can carbimazole cause?
neutropenia and agranulocytosis which could cause bone marrow suppression
should always check WBC count
congential malformations - use at risk in pregnancy
ACUTE PANCREATITIS - stop immediately if this occurs
what is the action of carbimazole?
blocks the way your body produces iodine .: cannot be used in making thyroid hormones
what medications used to treat hypothyroidism?
levothyroxine
what is a contraindication of levothyroxine?
thyrotoxicosis
what are the side effects of levothyroxine?
Angina pectoris, anxiety, arrhythmias, arthralgia, diarrhoea, dyspnoea, fever, flushing, headache (many more)
what is the second line drug treatment of hyperthyroidism?
propylthiouracil
what risks does propylthiouracil have?
severe liver reactions
including death
patient on carbimazole has a sore throat. what is happening?
carbimazole can cause agranulocytosis
they need an urgent FBC and aggressive treatment of any infection
what are the rules for iodine therapy in hyperthyroidism?
- Women must not be pregnant or breastfeeding and must not get pregnant within 6 months of treatment
- Men must not father children within 4 months of treatment
Limit contact with people after the dose, particularly children and pregnant women
what is a side effect of radioactive iodine therapy in hyperthyroidism?
underactive thyroid
.: may need levothyroxie
what is the role of the parathyroid glands?
regulate serum calcium and phosphate levels via the secretion of parathyroid hormone (PTH) from chief cells.
what cells parathyroid hormone?
cheif cells
what can cause primary hyperparathyroidism?
adenoma (most common)
hyperplasia
carcinoma
what are the complications of primary hyperparathyroidism?
osteoporosis
renal impairement
pancreatitis
CVD
what is primary hyperparathyroidism
- More or one of the parathyroid glands is over-secreting PTH despite normal serum calcium
- Leads to hypercalcaemia.
what is secondary hyperparathyroidism?
- Due to a disorder in calcium-phosphate-bone metabolism
Causes the parathyroid glands to secrete PTH
what are the main causes of secondary hyperparathyroidism?
CKD
vit D deficiency
what is tertiary hyperparathyroidism?
- Following a prolonged period of hyperparathyroidism.
- Glands become hyperplastic and secrete PTH autonomously
patient shows increased PTH and increased Ca2+. what does this mean?
primary hyperparathyroidism
patient shows high PTH and low Ca2+. what does this mean?
secondary hyperparathyroidism
what is the typical presentation of hyperparathyroidism?
stones, bones, moans and groans
· Fatigue · Polyuria and polydipsia · Constipation · Abdominal pain · Vomiting · Confusion · Depression · Bone pain Renal stones
what imaging can be done in suspected hyperparathyroidism?
- DEXA scan: to assess for reduce bone mineral density - osteoporosis
- Ultrasound of renal tract: looking for renal stones
- Ultrasound of the neck: pre-operative planning and to identify adenomas (first-line)
- Nuclear imaging (eg sestamibi scan): for pre-operative planning and to identify adenomas (first-line)
what is the management for acute, severe hypercalcaemia related to hyperparathyroidism?
- IV fluids
- Bisphosphates: preserve bone density and reduce fracture risk
- Cinacalcet (a calcium-sensing receptor agonist): reduces PTH secretion and thus serum calcium. Used in primary hyperparathyroidism when surgery isn’t appropriate, declined or unsuccessful
what is the management for secondary hyperparathyroidism?
- Treat the underlying cause
- Cinacalcet if this fails or if patient is on dialysis
- Phosphate binders and calcium/vit D supplements for those who have chronic kidney disease
what is the treatment for tertiary hyperparathyroidism?
- Surgical intervention (partial parathyroidectomy)
- Residual parathyroid tissue is reimplanted elsewhere in the body - more accessible if future problems arise
where is cortisol secreted from?
adrenal glands
what controls the release of cortisol?
hypothalamus
what are the normal levels of cortisol throughout the day?
diurnal variation
cortisol peaks in the early morning, triggering us to wake up and get going
lowest late in the evening, prompting us to relax and fall asleep.
what is the mechanism that leads to cortisol release?
hypothalamus releases corticotropin-releasing hormone (CRH)
CRH acts on anterior pituitary to release adrenocorticotropic hormone (ACTH)
ACTH stimulates adrenal gland to release cortisol
where is adrenocorticotropic hormone released from?
anterior pituitary
what stimulates the release of adrenocorticotropic hormone?
corticotropin releaseing hormone
what is the adrenal axis controled by?
negative feedback
keeps cortisol regulated in normal limits
what are the actions of cortisol in the body?
○ Increases alertness
○ Inhibits the immune system – inhibits the production of several inflammatory cytokines
○ Inhibits bone formation – chronically elevated cortisol can lead to osteoporosis)
○ Raises blood glucose – stimulating gluconeogenesis (synthesis of glucose from non-carbohydrate sources)
○ Increases metabolism – promoting breakdown of proteins which can result in muscle wasting in chronic states of cortisol elevation
○ An initial surge in cortisol levels triggers lipolysis, however, chronically elevated cortisol promotes lipogenesis.
what is cushings syndrome?
prolonged high levels of glucocorticoids in the body.
cortisol
what are the symptoms of cushings syndrome?
- Weakness
- Facial fullness
- Weight gain
- Low mood
- Decreased libido
- polydipsia
- polyuria
Increased frequency of infection
what clinical signs of cushings syndrome?
- Round face (known as a “moon face”)
- Central (truncal) obesity
- Abdominal striae (stretch marks)
- Enlarged fat pad on the upper back (known as a “buffalo hump”)
- Proximal limb muscle wasting (with difficulty standing from a sitting position without using their arms)
- Male pattern facial hair in women (hirsutism)
- Easy bruising and poor skin healing
- Hyperpigmentation of the skin in patients with Cushing’s disease (due to high ACTH levels)
○ ACTH is stimulating melanocytes to produce melanin
○ This is absent if the cause is an adrenal adenoma or exogenous steroids - Hypertension
- Signs of tumour in Cushing’s disease e.g. headaches, visual field defects
what are the main causes of cushings syndrome?
- C – Cushing’s disease (a pituitary adenoma releasing excessive ACTH)
- A – Adrenal adenoma (an adrenal tumour secreting excess cortisol)
- P – Paraneoplastic syndrome – ACTH is released from a tumour somewhere other than the pituitary gland (ectopic ACTH) stimulating excessive cortisol release from the adrenal gland e.g. small cell lung cancer
- E – Exogenous steroids (patients taking long-term corticosteroids)
what are the 2 types of causes of cushings syndrome?
endogenous = pituitary adenoma, adrenal adenoma, adrenal carcinoma
exogenous = prolonged use of corticosteroids e.g. prednisolone/dexamethasone
what is the main test used in investigating cushings syndrome?
dexamethasone suppression test
what is the low dose overnight dexamathasone test?
dexamethasone (1mg) is given at night (usually 10 or 11 pm), and the cortisol is checked at 9 am the following morning.
* Normal result = cortisol level is suppressed. * Failure of the dexamethasone to suppress the morning cortisol could indicate Cushing’s syndrome, and further assessment is required.
what is the lowdose 48hr dexamethasone test?
dexamethasone (0.5mg) is taken every 6 hours for 8 doses, starting at 9 am on the first day. Cortisol is checked at 9 am on day 1 (before the first dose) and 9 am on day 3 (after the last dose).
* Normal result = cortisol level on day 3 is suppressed. * Failure of the dexamethasone to suppress the day 3 cortisol could indicate Cushing’s syndrome, and further assessment is required.
what is the high dose 48hr dexamethasone test?
carried out the same way as the low-dose test, other than using 2mg per dose (rather than 0.5mg).
* higher dose is enough to suppress the cortisol in Cushing’s syndrome caused by a pituitary adenoma (Cushing’s disease), * not when it is caused by an adrenal adenoma or ectopic ACTH.
what is the test when ACTH is measured directly in the dexamethasone test?
- ACTH is suppressed due to negative feedback on the pituitary when excess cortisol comes from an adrenal tumour (or endogenous steroids)
ACTH is high when produced by a pituitary tumour or ectopic ACTH (e.g., small cell lung cancer
dexamethasone test shows these results:
low dose test = low cortisol
high dose test = low cortisol
ACTH = normal
what does this show?
normal
dexamethasone test shows these results:
low dose test = cortisol not supressed
high dose test = cortisol not supressed
ACTH = low
what does this show?
adrenal adenoma causing cushing
dexamethasone test shows these results:
low dose test = cortisol not suppressed
high dose test = low cortisol
ACTH = high
what does this show?
pituitary adenoma causing cushings
dexamethasone test shows these results:
low dose test = cortisol not suppressed
high dose test = cortisol not suppressed
ACTH = high
what does this show?
ectopic ACTH causing cushings
what is the 24hr urinary free cortisol test?
used in cushings
* An alternative to the dexamethasone suppression test.
* cumbersome to carry out and does not indicate the underlying cause
Cortisol excretion of more than 3 times the upper limit of normal is strongly suggestive of Cushing’s syndrome
what is the late night salivary cortisol measurement test?
- Simple and reliable test
- Normal = level of cortisol decreases in the evening compared to morning
Cushing’s syndrome = normal diurnal variation is absent
- Normal = level of cortisol decreases in the evening compared to morning
what is inferior petrosal sinus sampling and why is it used in cushings?
- Invasive procedure where ACTH levels are sampled from veins that drain the pituitary gland
- These ACTH levels are compared to peripheral ACTH levels to determine whether a pituitary tumour is the cause
Used when neuroimaging and previous investigations has not reached a diagnosis
- These ACTH levels are compared to peripheral ACTH levels to determine whether a pituitary tumour is the cause
what is the management of cushings syndrome?
(C) Pituitary adenoma
Trans-sphenoidal (through the nose) removal of the tumour
May also require adjunct radiotherapy
(A) Adrenal tumour
Surgical removal – laparoscopic excision
(P) Ectopic ACTH
Surgical removal of the tumour (e.g. small cell lung cancer) if possible
(E) Exogenous steroids
Review patients current glucocorticoid treatments and reduce doses where possible
- could surgically remove both adrenal glands and then give lifelong steroid replacement
- Metyrapone, ketoconazole + mitotane all reduce the production of cortisol in the adrenals (inhibit glucocorticoid synthesis) and is occasionally used in treating of Cushing’s.
Either used as long term treatment if patient is unfit to have surgery or short term before surgery
- Metyrapone, ketoconazole + mitotane all reduce the production of cortisol in the adrenals (inhibit glucocorticoid synthesis) and is occasionally used in treating of Cushing’s.
what are the complications of cushings syndrome?
- hypertension
- diabetes
- obesity
- Metabolic syndrome
Osteoporosis
what is addisons disease?
primary adrenal insufficiency
when adrenal glands are damaged -> reduced cortisol and aldosterone secretion, most common cause is autoimmune.
what is adrenal insufficiency?
where the adrenal glands do not produce enough steroid hormones, particularly cortisol and aldosterone. Steroids are essential for life. Therefore, the condition is life-threatening unless the hormones are replaced.
what is secondary adrenal sufficiency?
inadequate adrenocorticotropic hormone (ACTH) and a lack of stimulation of the adrenal glands, leading to low cortisol.
This is the result of loss or damage to the pituitary gland.
What are some causes of secondary adrenal insufficiency?
▪ Tumours (e.g., pituitary adenomas)
▪ Surgery to the pituitary
▪ Radiotherapy
▪ Sheehan’s syndrome = where major post-partum haemorrhage causes avascular necrosis of the pituitary gland
Trauma
what is tertiary adrenal insufficiency?
inadequate corticotropin-releasing hormone (CRH) release by the hypothalamus.
○ Usually the result of patients taking long-term oral steroids (for more than 3 weeks), causing suppression of the hypothalamus (via negative feedback) ○ When the exogenous steroids (originating outside the body) are suddenly withdrawn, the hypothalamus does not “wake up” fast enough, and endogenous steroids (originating inside the body) are not adequately produced Long-term steroids must be tapered slowly to allow the adrenal axis to regain normal function.
what are the symptoms of addisons disease?
- Fatigue
- Muscle weakness
- Muscle cramps
- Dizziness and fainting
- Thirst and craving salt
- Weight loss
- Abdominal pain
- Depression
- Reduced libido (mainly in women)
Loss of hair in axillary/pubic regions (mainly in women)
what are the clinical signs of addisons disease?
- Bronze hyperpigmentation of the skin (particularly in creases, scars, lips and buccal mucosa) = excessive ACTH stimulates melanocytes to produce melanin
Hypotension (particularly postural hypotension – with a drop of more than 20 mmHg on standing)
what endocrine disorder commonly presents with bronze hyperpigmentation of the skin?
addisons disease
what blood results are seen in addisons disease?
- Hyponatraemia (low sodium) is a key biochemical finding. This may be the only presenting feature.
Other potential biochemical findings may occur. Normal results do not exclude the diagnosis:
○ Hyperkalaemia (high potassium)
○ Hypoglycaemia (low glucose)
○ Raised creatinine and urea due to dehydration
Hypercalcaemia (high calcium)
what is the key biochemical finding in addisons disease?
hyponatraemia
what does the early morning cortisol test show in adrenal insufficeincy?
(8 – 9 am) has a role but is often falsely normal and does not distinguish between the types of adrenal insufficiency
- < 100 nmol/L: adrenal insufficiency very likely
- 100–500 nmol/L: adrenal insufficiency possible
> 500 nmol/L: adrenal insufficiency unlikely
- 100–500 nmol/L: adrenal insufficiency possible
what do the levels of ACTH show in the types of adrenal insufficiency?
ACTH level high = primary adrenal insufficiency, as the pituitary is producing lots of ACTH without negative feedback in the absence of cortisol.
ACTH level low = secondary/tertiary adrenal failure.
what is the gold standard investigation in addisons disease and what results are shown?
Short Synacthen Test
* Also known as the ACTH stimulation test. It is the test of choice for diagnosing adrenal insufficiency.
It is ideally performed in the morning.
The test involves giving a dose of Synacthen (synthetic ACTH)/ IV administration of 250mcg of tetracosactide (synthetic ACTH).
The blood cortisol is checked before and 30 and 60 minutes after the dose.
○ Normal = cortisol level should at least doubel,synacthen will stimulate healthy adrenal glands to produce cortisol. ○ Failure of cortisol to double indicates either: ▪ Primary adrenal insufficiency (Addison’s disease) ▪ Very significant adrenal atrophy after a prolonged absence of ACTH in secondary adrenal insufficiency
what is the management of adrenal insuffiency?
- Hydrocortisone 15-30mg/day divided into doses(a glucocorticoid) is used to replace cortisol.
- Fludrocortisone 50-300mcg/day (a mineralocorticoid) is used to replace aldosterone, if aldosterone is also insufficient.
what is done to steroid doses in acute illness?
doubled
what is an adrenal crisis?
Adrenal crisis, also known as Addisonian crisis, describes an acute presentation of severe adrenal insufficiency, where the absence of steroid hormones leads to a life-threatening emergency
what is the presentation of an adrenal crisis?
- Reduced consciousness
- Hypotension
- Hypoglycaemia
Hyponatraemia and hyperkalaemia
what is the management of an adrenal crisis?
- ABCDE approach to initial assessment and arrange transfer to hospital
- Intramuscular or intravenous hydrocortisone (the initial dose is 100mg, followed by an infusion or 6 hourly doses)
- Intravenous fluids
- Correct hypoglycaemia (e.g., IV dextrose)
Careful monitoring of electrolytes and fluid balance
list the hormones produced in the anterior pituitary?
ACTH
FSH
GH
LH
prolactin
TSH
list the hormones produced the posterior pituitary?
ADH
oxytocin
what is the difference between the anterior and posterior pituitary?
anterior = makes and releases hormones
posterior = stores and releases hormones rhat the hypothalamus has made
what is hypopituitarism?
Hypopituitarism happens when the pituitary gland is not active enough. It does not make enough hormones. Hypopituitarism can directly affect the pituitary gland. Or it can indirectly affect the gland through changes in the hypothalamus. Symptoms depend on which hormones the pituitary gland is not making enough of.
what is seen in someone with a growth hormone deficiency?
- Fatigue
- Muscle weakness
- Changes in body fat composition
- Lack of ambition
Social isolation
in children it may cause growth problems and short statures
what symptoms are seen when women have gonadotropin deficiencies?
○ Hot flashes
○ Irregular or no periods
○ Loss of pubic hair
An inability to produce milk for breast-feeding
what symptoms are seen when men have gonadotrophin deficiencies?
§ Erectile dysfunction
§ Decreased facial or body hair
Mood changes
what symptoms are seen in ACTH deficiency?
® Severe fatigue
® Low blood pressure, which may lead to fainting
® Frequent and prolonged infections
® Nausea, vomiting or abdominal pain
Confusion
what symptoms are seen in diabetes insipidus?
◊ Excessive urination
◊ Extreme thirst
Electrolyte imbalances
what is an ADH deficiency known as?
diabetes insipidus
what is the main cause of prolactin deficiency?
pituitary tumor - prolactinoma
what are the signs and symptoms of prolactinomas?
women:
Irregular or no periods (as prolactin decreases FSH/LH)
Reduced fertility
Reduced sex drive
Galactorrhea
Increased hair growth on face and body
men
Reduced fertility
Erectile dysfunction
Reduced sex drive
Breast enlargement
Galactorrhea
children
Reduced growth
Delayed puberty
what is the management of prolactinomas?
not treating - if its small and symptoms arent troublesome
dopamine agonists e.g. bromocriptine, cabergoline, quinagolide - shrink tumour and reduce prolactin released
surgery = trans-sphenoidal
what is acromegaly?
hypersecretion of pituitary growth hormone, usually as a result of a pituitary tumour, which leads to an abnormal increase in size of the skeletal extremities.
what are the symptoms of acromegaly?
· Onset often slow and insiduous, most often diagnosed in middle age. Men and women are equally affected.
· Growth of hands and feet
· Change in facial features – widening bridge of nose, thick lips, protruding jaw and brow, macroglossia, teeth seperation
· Headaches and visual disturbance due to tumour
· Deeper voice
· Skin tags, excessive sweating. Mild hirsuitism in women.
· Joint pain and carpal tunnel syndrome.
· Hypertension and diabetes
· Organomegaly (liver/spleen/goitre)
what is the gold standard invesitgation for acromegaly?
oral glucose tolerence test
glucose should supress GH
normal = normal IGF1
acromegaly = raised IGF1
what is the first line treatment of acromegaly? and what is the first line drug treatment?
endoscopic trans-sphenoidal surgery
radiotherapy as an adjuvent
somatostatin analogues e.g. octreotide
sometimes dopamine agonists e.g. bromocriptine
what is diabetes insipidus?
Diabetes Insipidus (DI) is a disorder caused by hyposecretion or insensitivity to ADH which leads to polydipsia, polyuria and large amounts of dilute urine.
what are the 2 types of diabetes insipidus?
- Cranial DI – caused by any condition which impairs the production, transportation or release of ADH which in turn reduces the process involved in the concentration of urine leading to polyuria and polydipsia.
- Nephrogenic DI – decreased inability to concentrate urine due to conditions within the renal collecting duct causing a resistance to ADH. There are also two minor forms of DI
what is suggested by impaired production, transportation or release of ADH leading tp increased conc of urine?
cranial diabetes insipidus
what is suggested by renal collecting duct having a resistance to ADH?
nephrotic diabetes insipidus
what are some symptoms of diabetes insipidus?
Polyuria
Large dilute vol of urine
Polydispsia
what are some causes of diabetes insipidus?
· Idiopathic
· Tumour of the brain- craniopharyngioma, germinoma, lymphoma
· Intracranial surgery
· Head injury
· Infection- encephalitis, meningitis
· Vascular disorder- aneurysms, sickle cell disease
Radiotherapy
what is the gold standard investigation for diabetes insipidus?
Record 24 hr urine = looking for >3L within 24hrs
what is the management of diabetes insipidus?
· Oral fluids encouraged
· Metabolic abnormalities are corrected if present
· Medication review for possible causes/worsening drugs
· If symptoms are mild (<4L urine per day) intervention is not usually advised
· Moderate cases – treated with Desmopressin.
· Can consider combination treatment involving thiazide diuretic and NSAID
In severe cases may require intermittent catheterization
what is an androgen secreting tumor?
make too much testosterone and can cause a virilizing (i.e. masculinizing) syndrome.
what are the symptoms of a woman with an androgen secreting tumour?
excessive facial and body hair growth, a receding hairline, acne, irregular menstrual periods, deepening of their voice (hirsutism) and ambiguous genitalia.
how is an androgen secreting tumour diagnosed?
high blood testosterone + DHEA-s levels + urine 17 ketosteroids
what surgery option is available for androgen secreting tumours?
open adrenalectomy with lymph node dissection ( these tumours have a high risk of spreading to lymph nodes.
what are some drugs that destroy adrenal tissue in an androgen secreting tumor?
mitotane
ketoconazole
what is a phaeochromocytoma?
rare, usually benign tumor that develops in an adrenal gland
what type of hormones are released from phaeochromocytomas? where are they released from?
catecholamines e.g. adrenaline and noradrenaline
usually from sympathetic preganglion cells in the adrenal medulla
what symptoms can be seen in a phaeochromocytoma?
- High blood pressure
- Headache
- Heavy sweating
- Rapid heartbeat
- Tremors
- Pallor
- Shortness of breath
- Panic attack-type symptoms
what complications are seen with a phaeochromocytoma?
High blood pressure can damage organs, particularly tissues of the heart and blood vessel (cardiovascular) system, brain and kidneys. This damage can cause several critical conditions, including:
* Heart disease * Stroke * Kidney failure * Problems with the nerves of the eye
when should a diagnosis of phaeochromocytoma be suspected most?
patient simultaneously presents with hypertension and the classic triad of heart palpitations, headaches, and profuse sweating.
what investigations are carried out in a suspected phaeochromocytoma?
Plasma + 3x24hr urinary metadrenaline and normetadrenaline
Abdominal CT or MRI (to detect adrenal tumours)
what is the management of a phaeochromocytoma?
Alpha blockade and beta blockade
Surgery, if malignant then chemotherapy and radiotherapy may be helpful
