Goitre is the enlargement of the thyroid gland; it may present as a solitary nodule, multiple nodules or diffuse depending on the etiology. Iodine deficiency is the most common cause for goitre worldwide, but relatively uncommon in developed countries.
5% of all goitres are cancerous.
Graves disease and toxic multinodular goitre (MNG) commonly present with hyperthyroid symptoms, others present as hypothyroid.
Etiology- Iodine deficiency (endemic goitre)
- Autoimmune – Hashimoto, post-partum thyroiditis, graves disease
- Iatrogenic – radioactive, thyroidectomy, drugs – (carbimazole, PTU, amiodarone)
- Congenital – thyroid aplasia, dyshormonogenesis
- Infiltrative – amyloidosis, sarcoidosis, riedel thyroiditis
- 2nd hypothyroidism – TSH deficiency
Pathology
- Prolong hypothyroidism > infiltration of MPS/HA/chondroitin sulphate > carpal tunnel, slurred speech, myxedema, lemon skin
- Diffuse goitre – simple, autoimmune thyroiditis, iodine deficiency
- Nodular – MNG, solitary nodular, fibrotic cysts
Clinical features
Hypothyroid symptoms- – Lethargy, weight gain, bradycardia, cold intolerance
- Goitre – painless, dysphagia/dyspnea
Diagnosis
- Record – size, shape, consistency, mobility
- Retrosternal extension if lower margin cannot be demarcated
- Thyroid functional tests – TSH, T4, T3
- Auto antibodies
- US / Xray / biopsy (FNAC/Trucut)
- Thyroid scan – I-123
Treatment
- Levothyroxine [50mcg]
Types of goitre
- Atrophic autoimmune – anti-thyroid antibodies cause infiltration of thyroid gland > atrophy and fibrosis
- Hashimoto – anti TPO antibodies
- Iodine deficiency – increase TSH leads to goitre formation