Case 7- Thyroid Disease Flashcards by pio monaghan

Graves ophthalmology features

Exophthalmos (proptosis)- anterior bulging of the eye out of the orbit
Opthalmoplegia
Conjunctival oedema
Upper eyelid retraction and lag
Inability to close eyelid

Give topical lubricants, steroids

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Unique features of Graves’ disease

Diffuse goitre (no nodules)
Graves eye disease
Pretibial myxoedema
Thyroid acropachy (clubbing, soft tissue swelling, periostea new bone formation)

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Investigations for Graves disease

Physical thyroid exam
Eye exam if opthalmopathy present
FBC- exclude infection (tachycardia/ sweating), UE, TFT
Thyroid antibodies and calcitonin/thyroglobulin markers- TRAb (exclude medullary, papillary and follicular thyroid cancer)
Thyroid ultrasound with FNA- if TRAbs low?
Radioactive iodine uptake (diffuse, homogenous, increased uptake)

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Graves’ disease antibodies

TRAb- specific
Anti TPO- non specific
Anti Tg- non specific

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Treatment of a Thyrotoxic storm

BLAH
Beta blocker (propranolol)
Lugols iodine
Anti thyroid drugs/thionamides (PTU)
Hydrocortisone

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Hashimoto’s thyroiditis antibodies

Anti TPO
Anti Tg

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Difference between Hashimotos and de Quervains

H- autoimmune, rarely hyperthyroid beforehand, and if it is present it is prolonged
DQ- viral infection (also painful/raised ESR), short initial hyperthyroid period

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Horner syndrome

Miosis
Partial ptosis
Facial anhidrosis

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Sx hyperthyroidism

Heat intolerance, sweating, weight loss, palpitations, tremor, tachycardia, goitre, irritability, onchylosis, oligomenorrhoea, decreased libido, graves specific features

NB- high output cardiac failure in the elderly

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Graves differentials

TMG, thyroiditis

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Sx hypothyroidism

Tiredness, lethargy, low mood, cold intolerance, increased weight, constipation, menorrhagia, hoarse voice, memory/cognitive impairment, myalgia, cramps, weakness, coarse hair, dry skin, expressionless face, rounded face, reflexes slow to relax, hair loss (lateral edge eyebrows), carpal tunnel syndrome

NB- hyperlipidaemia

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Thyroid cancer Sx

Painless, palpable thyroid nodule (no Sx of hyperthyroidism or hypothyroidism)

Advanced symptoms include;
Hoarseness, dyspnoea, dysphagia, cervical lymphadenopathy, tracheal deviation, Horner syndrome

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Thyroid nodule investigations

Thyroid exam
FBC UE- see if fit for surgery, exclude infection, Ca (spread to bone)
TFT’s (unchanged in cancer- cold nodules)
Tumour markers or thyroid antibodies- calcitonin (medullary carcinoma) thyroglobulin (follicular/ papillary)
Ultrasound scan (gold standard) and FNA
Thyroid scintigraphy (radioiodine uptake- cold nodules are malignant)
Staging- CXR, HEAD, NECK CT SCAN

NB- remember the markers and cancer types as: MC TFP

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Hashimoto’s thyroiditis

Features of hypothyroidism (rarely preceded by a thyrotoxicosis phase where the thyroid hormone is dumped out- causes a diffuse, lumpy painless goitre and hyperthyroidism Sx, but only in rare circumstances and lasts for several months, unlike de Quervain’s hyperthyroid period which only lasts a few weeks)

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De Quervains Thyroiditis

AKA- subacute thyroiditis

Triphasic pattern- very short period of hyperthyroidism, then hypothyroidism, then back to euthyroidism

Usually a self limiting viral infection (normally only needs aspirin- steroids in severe cases)

Painful goitre, raised ESR
Thyroid scintigraphy- global reduced uptake of iodine 131

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Post partum thyroiditis

First hyperthyroid
Then hypothyroid
Then back to euthyroid (within a year)

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Sub clinical disease

Sub clinical hypothyroidism- raised TSH, normal T3/4

Sub clinical hyperthyroidism- low TSH, normal T3/4

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Secondary hyperthyroidism

TSH secreting adenoma (different set of results)

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Secondary hypothyroidism

Pituitary/ hypothalamic failure

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T4 vs T3

Free T4 is better to monitor- more of it (a lot of T3 produced from T4 (peripheral conversion))

BUT- T3 is the active hormone

FNA and cytology of thyroid nodules

Thy1- do again
Thy2- benign
Thy3- intermediate
Thy4- suspicious of malignancy
Thy5- diagnostic of malignant

Radioiodine outcomes

Malignancy- cold nodule

Graves- increased uptake diffusely

TMG- mixed hot and cold nodules (patchy)

Toxic adenoma- 1 hot nodule

Thyroiditis- reduces uptake

Hyperthyroidism treatment regimens

Carbimazole can either be titrated to maintain normal levels (titration block)- more suitable as done over a longer term and suitable in pregnancy (other one isn’t)

The dose blocks all production of thyroid hormone, and then takes levothyroxine until they are euthyroid (block and replace)

Management of Graves’ disease

Graves’ disease patients should be referred to secondary care
Beta blocker
ATD- carbimazole (12-18 months)
Radioiodine treatment (relapse or resistant to ATD therapy)
Thyroidectomy

Management of hypothyroidism

Levothyroxine (cardiotoxicity- cardiac ischaemia/ AF, be careful) Regular monitoring

Papillary cancer

Most common Good prognosis, although spreads early Thyroglobulin Young women

Follicular carcinoma

Encapsulated Second most common Thyroglobulin

Medullary carcinoma

Third most common Calcitonin often raised MEN2- family history, symptoms of pheochromocytoma M for M (MEN and Medullary)

Anaplastic carcinoma

Rare Old women Poor prognosis as treatment resistant and frequently invades

Carbimazole MOA

Blocks thyroid peroxidase from coupling and iodinating tyrosine residues on thyroglobulin Associated with agranulocytosis- sore throat

Contraindications to radio iodine treatment

Pregnancy (avoid 4-6 months following) Below 16 NB- many will require thyroxine 5 years after treatment

Associations of Hashimoto’s thyroiditis

Autoimmune conditions eg. Coeliac disease, T1DM MALT lymphoma

Amiodarone and the thyroid gland

Can cause hypothyroidism and hyperthyroidism continue in hypo, stop in hyper (can use either carbimazole/steroids/potassium perchlorate)

Rare secondary causes of hypothyroidism

Pituitary failure Down’s syndrome

Rare primary causes of hypothyroidism

Iodine deficiency Lithium

Side effects of levothyroxine therapy

Hyperthyroidism (over treatment) Reduced bone mineral density Worsening of angina AF Interacts with iron and calcium carbonate (absorption reduced, so give at least 4 hours apart)

Myxoedema coma

Typically presents with confusion and hypothermia IV thyroid replacement and fluids IV corticosteroids

ATD’s in pregnancy

Propylthiouracil in 1st trimester Carbimazole in 2nd and 3rd No radioiodine

Hypothyroidism and pregnancy

Thyroxine is safe Increase thyroxine by 50% as early as 4-6 weeks pregnancy

Sick euthyroid syndrome

Low T3 and T4 (thyroxine) Normal TSH No treatment needed

Subclinical hyperthyroidism

Normal T3 and T4 Low TSH Usually untreated but can offer low dose ATD for 6 months

Subclinical Thyroid Disease

Subclinical Hypothyroidism TSH raised but T3, T4 normal -consider offering levothyroxine if the TSH level is > 10 mU/L on 2 separate occasions 3 months apart -if < 65 years consider offering a 6-month trial of levothyroxine if: the TSH level is 5.5 - 10mU/L on 2 separate occasions 3 months apart, and there are symptoms of hypothyroidism in older people (especially those aged over 80 years) follow a 'watch and wait' strategy is often used if asymptomatic people, observe and repeat thyroid function in 6 months Subclinical Hyperthyroidism a therapeutic trial of low-dose ant thyroid agents for approximately 6 months in an effort to induce a remission

Most common cause of hypothyroidism

Developed world- Hashimoto’s Undeveloped world- iodine deficiency

Poor thyroxine compliance biochemistry

High TSH Normal T4 (TSH lags behind if patient has just taken thyroxine in recent days)

Management of a TMG

Radioiodine therapy

What marker is used to guide treatment success in hypothyroidism?

TSH

Grading Graves ophthalmology

The severity of Grave's eye disease can be graded using the mnemonic NOSPECS No signs / symptoms Only signs (e.g: upper lid retraction) Signs & symptoms (including soft-tissue involvement) Proptosis Extra-ocular muscle involvement Corneal involvement Sight loss due to optic nerve involvement

Thyroglossal cyst

Reassure- no surgery