thyroid disease and malignancy Flashcards
what does hypothalamus release to pituitary and what does this do
TRH
stimulates thyrotrophs to produce TSH
Role of TSH
Stimulates increased thyroidal iodine uptake by thyroid and synthesis of t3 and t4
-COnversion of t4 to t3 stimulated by TSH in peripheral tissues
what is compensated euthyroidism
if t4/3 low, increased TRH and tSH to increase T4/3. T3/4 now normal but increased TSH drive resulting in high TSH
What are some autoimmune causes of hypothyroidism
Atrophic thyroiditis
Hashimotis
Post partum thyroiditis
What are some defects of hormone synthesis causes of hypothyroidism
iodine deficiency
Dyshormogenesis
Anti-thyroid drugs
What are some post irradiation causes of hypothyroidism
Radioactive thyroid therapy
External neck irradiation
features of hashimotos
-What are clinical features
Thyroid firm and rubbery on palpation but may be soft
-TPO antibodies present
Atrophic autoimmine thyroiditis features
-WHy can this sometimes resolve
Associated with antithyroid autoantibodies leading to lymphoid infiltration of the gland and atrophy and fibrosis
-If autoantibodies that block the tsh receptor are the cause
Features of post party thyrotoxicosis
transient lymphocytic thyroiditis that can also cause hyperthyroidism
-WOmen present with post party depression should have tft
how does hypo display in children
may not show classic symptoms but can grow poorly, perform poorly at school and may not develop at puberty. Babies are assessed for congenital hypothyroidism in the heel-prick test.
hypo in young women>
hypothyroidism should be excluded in patients that present with problems with menstruation (dysmenorrhoea, oligomenorrhoea, menorrhagia, infertility).
Signs of hypothyroidism
tiredness Weight gain Bradycardia Slow relaxing reflexes Mental slowness Dry skin\Dry thinning hair/brows
what tests to do if patient is hypothyroid and hashimotis disease is suspected
- Thyroid peroxidase antibodies (TPOAb) [raised]
- thyroglobulin antibodies (TgAb) [may be raised]
autoimmune causes of hyperthyroidism
Graves
Toxic multonodular goire
Solitary toxic nodule/adenoma
Acute thyroiditis causes of hyperthyroidism
Viral (de-Quervain’s), autoimmune
aetiology of graves (hyper)
serum IgG autoantibodies attach to TSH receptors in the thyroid gland, stimulating thyroid hormone production. These thyroid-receptor antibodies (TSH-rAb) are specific to Graves’ disease.
Features of solitary nodule/adenoma
Firm painless lump in neck. Mobile when swallowing.
Features of toxic multi nodular goitre
Often occurs in women
Features of de quervains thyroiditis
transient hyperthyroidism associated with inflammatory process
(viral infection). Fever, malaise, pain in the neck and tachycardia; can cause hypothyroidism after initial over-active phase. Acute phase treatment is with aspirin and steroids may given in severe cases.
Clinical features of hyperthyroidism
AF, tachycardia or HF Increase in height and behavioural problems in children Lid lag and stare Thyroid acropachy: clubbing, swollen fingers and periosteal new bone formation Heat intolerance goitre Thyroid bruit Full pulse, warm vasodilator peripheries
what ro test for to confirm graves
TSH receptor antibodies (TSHR-Ab).
Thyroid peroxidase antibodies (TPO-Ab)
risk of antithyroid drugs
Agranulocytosis
Treatment options of hyper
Drugs
Radioiodine therapy (iodine taken up and localised radiation destroys the gland)
Thyroidectomy
most likely cause of diffuse goitre
smooth soft enlargement with no apparent cause; if hypothyroid- Hashimotos thyroiditis: hyperthyroid likely Graves’ disease.
