Thyroid

Question 1

Name 5 causes hypothyroidism

Answer 1

Auto immune
• Hashimoto’s thyroiditis (antithyroid peroxidase antibodies and anti thyroglobulin antibodies)

Lifestyle
• iodine deficiency

Medications
• Lithium, amiodarone
• treatment for hyperthyroid: carbimazole, propylthiouracil, radioactive iodine, (thyroid surgery )

Medical conditions
• secondary hypothyroidism aka hypopituitarism not producing enough tsh: tumours, infection, vascular eg Sheehan syndrome, radiation

Question 2

Name 7 symptoms hypothyroidism

Answer 2

• Weight gain
• constipation
• heavy or irregular periods
. Fluid retention (Edema, pleural effusion, Ascites )
• fatigue
• dry skin
• coarse hair and hair loss

Question 3

Name 4 causes hyperthyroidism

Answer 3

Autoimmune
• graves disease

Surgical conditions
• Plummer’s disease or toxic multinodular goitre
• solitary toxic thyroid nodule
• thyroiditis eg de quervain, hashimoto’s, postpartum, drug induced

Question 4

Name 7 universal features hyperthyroidism

Answer 4

• weight loss
• fatigue
• sexual dysfunction
• diarrhoea
• sweating and heat intolerance
• anxiety and irritability
• tachycardia

Question 5

Name 4 unique features of Grave’s disease

Answer 5

• diffuse goitre without nodules
• graves eye disease
• bilateral exophthalmos
• pretibial myxoedema

Question 6

Name 2 unique features of toxic multinodular goitre

Answer 6

• goitre with firm nodules
• patients older than 50

Question 7

Name 2 most common causes thyroid goitre

Answer 7

Iodine deficiency
Autoimmune disorders: Hashimoto hypothyroid, Graves hyperthyroid

Question 8

Clinical triad of Grave’s disease?

Answer 8

• hyperthyroid
• goitre
• exophthalmos

Question 9

Approach to thyroid examination?

Answer 9

Inspect: size, site, shape, movement on swallowing! (If thyroid mass, will move up. Malignancy may not move), eye changes eg exophthalmos, Pemburton sign, Berry sign, protrude tongue (thyroglossal cyst will move up, thyroid gland mass won’t), erythema, scars previous thyroidectomy

Palpation from behind: consistency, tender, fixation to adjacent tissues, retrosternal extension, cervical lymphadenopathy, symmetry (unilateral enlarge = nodule or malignancy), nodules, palpable thrill (hyperthyroid, Grave’s), trachea deviation

Percussion sternum: retrosternal dull = large thyroid mass

Auscultation : bruit (Grave’s)

Question 10

What is Pemburton sign?

Answer 10

Elevation of upper limbs cause venous congestion of neck and face - indicate retrosternal component of thyroid mass

Question 11

What is Berry sign.?

Answer 11

Absence distal carotid pulsation (highly suspicious thyroid malignancy)

Question 12

Surface anatomy thyroid gland?

Answer 12

Palpable inferolateral to cricoid cartilage

Question 13

TFT in primary hyperthyroidism?

Answer 13

• Decrease tsh
• increase t3t4

Question 14

TFT in secondary hyperthyroidism?

Answer 14

• High tsh
• high t3t4

Question 15

TFT in primary hypothyroidism?

Answer 15

• Tsh high
• t3 t4 low

Question 16

TFT in secondary hypothyroidism?

Answer 16

• tsh low
• t3 t4 low

Question 17

Further investigations for primary hyperthyroidism?

Answer 17

Radioisotope scan: 123I or 99m Tc pertechnetate scan to determine cause hyper secretion

Question 18

What may a radioisotope scan done to investigate primary hyperthyroid reveal?

Answer 18

• Increased uptake (increased production t3t4): Graves’ disease, autonomous nodule, Plummer’s disease
• Normal or decreased uptake (not producing more but releasing everything it has): acute or subacute thyroiditis, drug induced, factitions, pregnancy

Question 19

Treatment primary hyperthyroidism with increased uptake radio-isotope scan?

Answer 19

Radioactive iodine ablation therapy
Carbimazole
Surgery if necessary

Nb to treat before biopsy, otherwise will cause thyroid storm

Question 20

Describe radioisotope scan findings of thyroid nodules (3)

Answer 20

• “Hot” hyperfunctioning nodule
• “warm” isofunctioning nodule (same as thyroid)
• “cold” non-functioning nodule. High risk malignancy

Question 21

Further investigations for thyroid goitre after tft? (4)

Answer 21

• Radioisotope scan if primary hyperthyroid
• Ultrasound - very sensitive for malignancy ( TIRADS classification)
• calcitonin if suspect medullary thyroid cancer
• thyroid biopsy (Bethesda system), nb to treat hyperthyroid first so don’t cause thyroid storm. Do FNA.

Question 22

Describe the Bethesda system, malignancy risk and treatment for thyroid

Answer 22

Thyroid cytopathology from FNA biopsy
1. NonDiagnostic or unsatisfactory , 1-4% risk malignancy, repeat FNA
2. Benign, 0-3%, observe
3. Atypia of undetermined significance or follicular lesion of undetermined significance, 5-15%, repeat FNA or surgery
4 follicular neoplasm or suspicious for a follicular neoplasm, 15-30%, repeat FNA or surgery
5. Suspicions for malignancy, 60-75%, surgery
6. Malignant, 97-99%, surgery

Question 23

Name and describe 4 types thyroid cancer

Answer 23

Well differentiated
• papillary (most common globally, spread via lymph )
• follicular (can never say for sure on cyto, need histo by surgery. Bethesda 4. Spread haematogenous )
• medullary (from parafollicular cells, produce calcitonin,investigate for men syndrome)

Undifferentiated
• anaplastic ( aggressive stage 4, Survival 3-6 months)

Question 24

Name 4 complications thyroid surgery

Answer 24

• recurrent laryngeal nerve injury (hoarse, dyspnoea if bilateral, bovine cough )
• external branch of superior laryngeal nerve injury ( cricothyroid muscle. Can’t say eee nicely)
• hypoparathyroid (hypocalcaemia- Chovstik sign, trousseau sign, cramps)
• haemorrhage
Hypothyroid-outcome not complication

Question 25

Name 5 indications thyroid surgery

Answer 25

• Malignancy risk or suspicious nodule
• compression symptoms on esophagus, trachea
• cosmetic
. Failed or contraindicated medical therapy hyperthyroid
• large retrosternal goitre

Question 26

What kind of adjuvant treatment can be done for thyroid carcinoma? (3)

Answer 26

• Hormone replacement therapy: prevent hypothyroidism and suppression therapy of any cells left behind by negative feedback tsh
• radio-active iodine ablation 2-12 weeks post op, do before suppression therapy
• external beam or intensity modulated radiotherapy: for medullary thyroid carcinoma.

Question 27

Name 5 causes thyroid goitre

Answer 27

•
Iodine deficiency
• hashimoto hypothyroid –
• graves hyperthyroid
• benign tumour
• malignant tumour
• physiological pregnancy
• nodules