Thyroid Flashcards
Name 5 causes hypothyroidism
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
Name 7 symptoms hypothyroidism
• Weight gain
• constipation
• heavy or irregular periods
. Fluid retention (Edema, pleural effusion, Ascites )
• fatigue
• dry skin
• coarse hair and hair loss
Name 4 causes hyperthyroidism
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
Name 7 universal features hyperthyroidism
- weight loss
- fatigue
- sexual dysfunction
- diarrhoea
- sweating and heat intolerance
- anxiety and irritability
- tachycardia
Name 4 unique features of Grave’s disease
- diffuse goitre without nodules
- graves eye disease
- bilateral exophthalmos
- pretibial myxoedema
Name 2 unique features of toxic multinodular goitre
- goitre with firm nodules
- patients older than 50
Name 2 most common causes thyroid goitre
Iodine deficiency
Autoimmune disorders: Hashimoto hypothyroid, Graves hyperthyroid
Clinical triad of Grave’s disease?
- hyperthyroid
- goitre
- exophthalmos
Approach to thyroid examination?
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)
What is Pemburton sign?
Elevation of upper limbs cause venous congestion of neck and face - indicate retrosternal component of thyroid mass
What is Berry sign.?
Absence distal carotid pulsation (highly suspicious thyroid malignancy)
Surface anatomy thyroid gland?
Palpable inferolateral to cricoid cartilage
TFT in primary hyperthyroidism?
• Decrease tsh
• increase t3t4
TFT in secondary hyperthyroidism?
• High tsh
• high t3t4
TFT in primary hypothyroidism?
• Tsh high
• t3 t4 low
TFT in secondary hypothyroidism?
• tsh low
• t3 t4 low
Further investigations for primary hyperthyroidism?
Radioisotope scan: 123I or 99m Tc pertechnetate scan to determine cause hyper secretion
What may a radioisotope scan done to investigate primary hyperthyroid reveal?
• 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
Treatment primary hyperthyroidism with increased uptake radio-isotope scan?
Radioactive iodine ablation therapy
Carbimazole
Surgery if necessary
Nb to treat before biopsy, otherwise will cause thyroid storm
Describe radioisotope scan findings of thyroid nodules (3)
• “Hot” hyperfunctioning nodule
• “warm” isofunctioning nodule (same as thyroid)
• “cold” non-functioning nodule. High risk malignancy
Further investigations for thyroid goitre after tft? (4)
• 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.
Describe the Bethesda system, malignancy risk and treatment for thyroid
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
Name and describe 4 types thyroid cancer
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)
Name 4 complications thyroid surgery
• 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
Name 5 indications thyroid surgery
• Malignancy risk or suspicious nodule
• compression symptoms on esophagus, trachea
• cosmetic
. Failed or contraindicated medical therapy hyperthyroid
• large retrosternal goitre
What kind of adjuvant treatment can be done for thyroid carcinoma? (3)
• 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.
Name 5 causes thyroid goitre
•
Iodine deficiency
• hashimoto hypothyroid –
• graves hyperthyroid
• benign tumour
• malignant tumour
• physiological pregnancy
• nodules
