Lecture 9: Clinical Thyroid Disease Flashcards
what are causes of Goitre?
- physiological: puberty, pregnancy
- autoimmune: Grave’s disease, Hashimoto’s disease.
- thyroiditis: acute (de Quervain’s), chronic fibrotic (Redidel’s)
- iodine deficiency (endemic goitre)
- dyshormonogenesis
- goitrogens
what are the different types of goitre?
- multinodular goitre
- diffuse goitre: colloid or simple
- cysts
- tumours: adenomas, carcinomas, lyphomas
- miscellaneous: sarcoidosis, tuberculosis
what investigations are performed for a solitary thyroid nodule?
- thyroid function test - (solitary toxic nodule)
- ultrasound: useful in differentiating benign vs malignant
- fine needle aspiration (FNA): Thy1: inadequate, Thy 2: benign to Thy 5: cancer
what is the most common endocrine system malignancy?
thyroid cancer
what are the two main types of thyroid cancer?
papillary:
- commonest
- multifocal, local spread to lymph nodes
- good prognosis
follicular:
- usually single lesion
- metastases to lung/bone
- good prognosis if resectable
management of thyroid cancer
- near total thyroidectomy
- high-dose radioiodine (ablative)
- long-term suppressive doses of thyroxine
follow-up:
- thyroglobulin
- whole body iodine scanning (following 2-4 weeks of thyroxine withdrawal or recombinant TSH injections)
- dynamic risk stratification (Tg and neck ultrasound)
describe the other, less common thyroid cancers
Anaplastic:
- < 5% of thyroid cancers
- aggressive, locally invasive
- very poor prognosis, do not respond to radioiodine, external RT may help briefly
Lymphoma:
- rare; may arise from preexisting hashimotos thyroiditis
- external RT more helpful, combined with chemotherapy
describe medullary thyroid cancer
- tumour arises from parafollicular C cells.
- often associated with MEN 2 (phaeochromocytoma & hyperparathyroidism)
- serum calcitonin levels raised
- treatment: total thyroidectomy, no role for iodine
- prognosis variable
what are the primary causes of thyrotoxicosis?
- Grave’s disease (70%)
- toxic multinodular goitre (20%)
- toxic adenoma
epidemiology of Grave’s disease
- 70-80% of all cases of hyperthyroidism
- incidence 2-2 per 1000 per year (sex ratio 5:1)
- prevalence: 1.9% female, 0.16% male
which autoantibodies are involved in Grave’s disease?
- TSH receptor auto-antibodies
- Thyroid peroxidase autoantibodies
diagnosis of Grave’s disease
- Thyroid function tests: hyperthyroidism (elevated T3 and T4 and suppressed TSH)
- blood tests: detecting TSH receptor antibodies.
describe multi-nodular goitre
- most common cause of thyrotoxicosis in the elderly
- characteristic goitre and absence of Grave’s disease
- will not go into spontaneous remission
features of subacute (de Quervain’s) thyroiditis
- generally younger patients < 50
- viral trigger (e.g. enterviruses, coxsackie)
- often recall painful goitre +/- fever/myalgia; ESR increased
- may require short-term steroid and NSAIDs.
give examples of antithyroid drugs (ATD)
carbimazole
propylthiouracil
amiodarone
lithium
