Causes
Sequence of events:
- Iodine deficiency leading to decreased T4 production.
- Induction of thyroid cell hyperplasia due to low levels of T4. This accounts for the multinodular goitre appearance.
- Increased replication predisposes to a risk of mutation in the TSH receptor.
- If the mutated TSH receptor is constitutively active, it would then become 'toxic' and produces excess T3/T4 leading to hyperthryoidism.
Read more about this topic: Toxic Multinodular Goitre