Thyroid Improved Flashcards

Question

Thyrotoxicosis differentials

Answer 1

``` Grave's Toxic Multinodular Goitre Toxic adenoma Destructive thyroiditis Excessive iodine (Jod-Basedow) Drugs Thyroid hormone Resistance TSH producing pituitary tumour - secondary hypothyroidism- raised TSH and FT4 ```

Answer 2

``` Autoimmune disease consisting one or more of: Thyroid dysfunction Ophthalmopathy Pre-tibial myxoedema Acropachy ```

Answer 3

``` Diffuse smooth goitre Bruit FH Other autoimmune (T1DM, Addison's, hypoparathyroidism, premature ovarian failure) Thyroid stimulating antibodies ```

Answer 4

``` Often smoker Pain Tearfulness + grittiness Dry Diplopia Prior to loss of visual acuity, loss of colour vision Redness Proptosis Lid lag + retraction ```

Answer 5

MRI orbits | TFTs

Answer 6

High dose Steroids Radiotherapy Surgery

Answer 7

Medical Radioiodine Surgery

Answer 8

Graves- 18 months of treatment Carbimazole Propylthiouracil Propanolol non selective BB (reduces acute symptoms as blocks catecholamine sensitive symptoms)

Answer 9

1 in 100 rash | 1 in 1000 agranulocytosis- warn about sore throat

Answer 10

``` Iodine 131 radiation- destroys gland Need to be away from children 2-3 weeks Can lead to hypothyroidism, so need to take thyroxine If Graves eyes, can deteriorate Used when carbimazole fails to cure ```

Answer 11

In presence of large goitre Need to be on thyroxine for rest of life Risk of damage to recurrent laryngeal- hoarseness Risk of damage to parathyroid glands- Vit D

Answer 12

Tired Cold Dry skin + hair

Answer 13

Weight gain | Constipation

Answer 14

Menorrhagia

Answer 15

``` Puffy Peaches and cream face Cold dry skin Goitre Bradycardia Slow relaxing reflexes In extremis- coma, hypothermia ```

Answer 16

Low FT4 High TSH Positive thyroid antibodies (Hashimoto's) Cortisol

Answer 17

If somebody has low Cortisol + ACTH, and give thyroxine to treat hypothyroidism, can precipitate into Addisonian crisis

Answer 18

``` Iodine deficiency (2 billion ppl worldwide) Hashimoto's thyroiditis Congenital hypothyroidism (1 in 4000) Iatrogenic Post-partum thyroiditis ```

Answer 19

If give iodine to those that are iodine deficient hypothyroidism, can become rapidly thyrotoxic

Answer 20

CT contrast is predominally iodine- if give CT contrast to someone with multinodular goitre, very likely to induce thyrotoxicosis

Answer 21

Levothyroxine- titrated to target TSH Titrate to make FT4 within upper half of reference (15-25 pmol/L) range, and TSH in lower half of reference range (0.5-2.5mU/L)

Answer 22

Consider cause How severe Does patient have co-morbidities

Answer 23

Intercurrent illness Inadequate dose malabsorption Poor concordance with therapy

Answer 24

ANY thyroid enlargement 1) Multi-nodular- more common in low iodine area 2) Secondary to autoimmune overactive or underactive thyroid (Grave's + Hashimoto) If it is toxic MNG, due to hyperthyroidism

Answer 25

``` Lump in neck- how long, has it changed, if sudden onset (bleed), slow onset (NG) Any thyrotoxicosis symptoms Dysphagia Cough/dyspnoea/stridor Sudden enlargement or pain ```

Answer 26

Size Retrosternal extension (percuss over sternum) Thyroid status Signs of airway compromise

Answer 27

``` TFT Lung function- tracheal compression CXR Ultrasound scan CT (without scan) ```

Answer 28

Watch + wait Surgery (thyroidectomy) Radioiodine (smaller goitre, can cause swelling so don't do on big one, can reduce 30-50%)

Answer 29

Neck lump/swelling | Radiation exposure?

Answer 30

Soft/firm/hard | Mobile/tethering

Answer 31

Ultrasound scan +/- fine needle aspiration Check calcitonin- raised in medullary cancer of thyroid Chest XR

Answer 32

Diagnostic hemithyroidectomy | Near-total thyroidectomy

Answer 33

Follicular adenoma (non-malignant) Papillary (lymphatic) Follicular (blood) Medullary (linked to multiple endocrine neoplasia type 2) Anaplastic- poor prognosis Lymphoma- rare 10 year disease free > 90% for papillary/follicular types

Answer 34

Near-total thyroidectomy helps to confirm histology- whether papillary/follicular cancer Adjunctive therapy- Iodine 131 ablation Suppressive thyroid replacement- high dose thyroxine to supress TSH + reduce recurrence External beam radiotherapy Serum thyroglobulin useful tumour marker- rising levels = recurrence

Answer 35

Increased (oestrogen inhibits hepatic breakdown) | Still normal T3/4 as increased total

Answer 36

Increase T3/4 Hypertrophy + hyperplasia of thyroid follicular cells Increased BF thyroid

Answer 37

Increase Na/K ATPase activity to increase O2 production and heat

Answer 38

``` Increased glucose uptake and absorption Increased glycogenolysis Increased Gluconeogenesis Increased insulin Increased FA oxidation Decreased cholesterol in plasma Decreased muscle mass ```

Answer 39

Increased HR and CO Increased vasodilation Increased ventilation

Answer 40

Increase DNS activity | Mental state: hyper- anxiety, nervous, hypo- sluggish

Answer 41

Increased growth plate chondrocytes and osteoblasts | Increase osteoclast activity (in thyrotoxicosis --> osteoporosis)

Answer 42

Thickens endometrium in females | Hypo associated with infertility

Answer 43

Potentiates growth | Potentiates foetal and neonatal brain development

Answer 44

High TSH | Low T4

Answer 45

High TSH | Negligible T4

Answer 46

High TSH | High T4

Answer 47

Low TSH High T4 Low T3

Answer 48

Low TSH | High T4 or 3

Answer 49

Low TSH | Negligible T4 and 3

Answer 50

Low TSH | Low T4

Answer 51

Low TSH | Low T4 and 3

Answer 52

Solitary focal, diffuse hyperplasia of follicular cells | Secrete thyroid hormones

Answer 53

Most common cause of thyrotoxicosis in iodine-deficient areas Also seen in elderly patients Nodules secrete excess thyroid hormones

Answer 54

Hormone synthesis not increase but instead destruction of thyroid follicular cells--> transient increase in thyroid hormones --> once they are 'exhausted' the patient becomes hypothyroid

Answer 55

Benign solitary nodule that creates pressure symptoms | May be painful if bleedsd

Answer 56

Increase in thyroid hormones- may trigger Graves 1st half- aggravated 2nd half- ameliorated Postpartum- recurrence

Answer 57

Normal T3 and T4 but suppressed TSH Increases risk of AG Endogenous causes – toxic adenoma, multinodular goitre Exogenous causes – levothyroxine

Answer 58

Mutation in receptor at pituitary- rise in T3 + 4 fails to suppress TSH Differential- TSHoma

Answer 59

Patients with MNG always relapse

Answer 60

``` HF Angina AF Osteoporosis Ophthalmopathy Gynaecomastia Thyroid Storm ```

Answer 61

Rare but life-threatening complication of thyrotoxicosis | It is typically seen in patients with established thyrotoxicosis and is rarely seen as the presenting feature

Answer 62

Recent thyroid surgery or radioiodine therapy Infection MI Trauma

Answer 63

``` Severe hyperthyroidism Fever Agitation Confusion Coma Tachycardia AF D+V Goitre Thyroid Bruit Acute abdomen HF ```

Answer 64

symptomatic treatment e.g. paracetamol treatment of underlying precipitating event beta-blockers: typically IV propranolol Anti-thyroid drughs- carbimazole 15-25mg/6h PO + after 4h give Lugol's iodine solution 0.3ml/8h PO to block thyroid Dexamethasone - 15-25mg/6h PO- blocks the conversion of T4 to T3 Treat infection if suspected- co-amoxiclav

Answer 65

Counteract peripheral effects of thyroid hormones Inhibit thyroid hormone synthesis Treat systemic complications

Answer 66

After 5 days reduce carbimazole to 15mg/8h PO After 10 days stop propranolol + Lugol's iodine and adjust carbimazole If no significant progress in 24hr, thyroidectomy

Answer 67

``` 70% Associated with radiation Young ppl (20-40) Females Follicular cell origin Ig Tumour markers Spreads- lymphatics, sometimes lung/bone mets Total thyroidectomy + node excision + radioiodine Prognosis- good, especially in young ```

Answer 68

``` 20% More common females (3:1) 40-60 Origin- follicular cells Ig Tumour markers Spread- haematogenous to lung/bone Treatment- total thyroidectomy + T4 suppression + radioiodine Prognosis- good if resectable ```

Answer 69

``` 5% 30% familial (MEN2) Affects young men 40-50 Origin- parafollicular cells Tumour markers- CEA + calcitonin Spread- local + metastases Treatment- thyroidectomy, node clearance +/- radioiodine Prognosis- poor, but indolent course ```

Answer 70

<5% Women (3:1), >60yrs Rapid + aggressive growth + spread Origin- undifferentiated follicular cells Spread- locally invasive Treatment- palliative- can try thyroidectomy +/- radioiodine V poor prognosis

Answer 71

2% In situ autoimmune thyroiditis or systemic lymphoma Origin- lymphocytes Treatment- chemo + radio

Answer 72

``` Thyroglossal cyst Branchial cyst Lymphadenopathy Pharyngeal pouch Dermoid cyst Lipoma Fibroma Salivary gland swelling Vascular- carotid body tumour or aneurysm ```

Answer 73

Uniform overall enlargement Simple euthyroid goitre- pregnancy, puberty Autoimmune thyroid disease- firm diffuse goitre seen in Hashimoto + Grave Thyroiditis- acute pain + tenderness in De Quervain's

Answer 74

Occurs after loss of thyroid structure Certain areas fibrosed + underactive MNG Solitary node- rule out malignancy, normally benign

Answer 75

Adenomas/carcinomas felt as lump

Answer 76

Low iodine --> hypothyroidism --> increased TSH --> growth of gland forming diffuse goitre --> some areas fibrose --> multinodular toxic goitre --> hyperthyroidism

Answer 77

high iodine (amiodarone, class 3 antiarrhythmic) --> destructive thyroiditis --> T4 and 3 release --> hyperthyroidism --> may become hypo after few months due to depletion + inhibition of deiodinase by drug

Answer 78

More common than hyper More common women (6:1) Excellent prognosis if treated Untreated --> Heart disease, dementia etc

Answer 79

Diffuse lymphocytic infiltration of thyroid --> atrophy (no goitre)

Answer 80

Rare initial period of hyperthyroid in hashimoto's thyroiditis

Answer 81

Not enough TSH due to hypopituitarism

Answer 82

``` Bradycardia Reflexes relax slowly Ataxia Dry thin hair/skin Yawning/drowsy/coma Cold Ascites +/- pitting oedema +/- pericardial or pleural effusion Round puffy face/double chin/obese Defeated demeanour Immobile CCF ```

Answer 83

``` Autoimmune- T1DM, Addisons, primary aldosteronism, primary biliary cholangitis Turners and Downs CF Ovarian hyperstimulation POEMS syndrome Genetic ```

Answer 84

``` Infection MI Stroke Trauma Thyroidectomy Radioiodine Pituitary surgery ```

Answer 85

``` Looks hypothyroid Often >65 Hypothermia Hyporeflexia Decreased glucose Bradycardia Psychosis Coma Seizures ```

Answer 86

``` Goitre Cyanosis Hypotension CCF Sign of precipitants ```

Answer 87

``` Bloods ABG for PaO2 Correct hypoglycaemia Give T 5-30 microg/12h IV slowly Give hydrocortisone if pituitary hypo suspected Infection- Abx fluid caution for heart Active warming ```

Answer 88

Levothyroxine 50-100 microg/daily PO before breakfast Review at 12 weeks Adjust every 6 weeks Once normal, check TSH yearly

Answer 89

TSH 0.5-2.5mU/L (lower ½ of RR) and free T4 15-25pmol/L (upper ½ of RR)

Answer 90

Enzyme inducer increase levothyroxine metabolism | Iron reduces absorption of levothyroxine, give at least 2 hours apart

Answer 91

 Start with Levothyroxine 25g/daily PO  Increase dose by 25g/4wks  Take caution as may precipitate angina or MI

Answer 92

increase in dose of 25-50microg is often needed to maintain normal TSH levels

Answer 93

Hyperthyroidism Decreased bone mineral density Worsening angina AF