thyroid tumours (benign)

Last edited 01/2020 and last reviewed 07/2021

The majority of benign tumours of the thyroid gland arise from the follicular epithelium and so, are follicular adenomas.

They usually present as solitary nodules less than 4 cm in diameter and clearly demarcated from the surrounding thyroid substance. Rarely, two or more adenomas are present.

Clinically, adenomas may:

  • cause pressure symptoms in the neck
  • suddenly enlarge and become painful due to intralesional haemorrhages
  • cause hyperthyroidism - but unassociated with the ophthalmopathy seen in Grave's disease
  • take up radioactive iodine - appear as "hot" nodules

A follicular adenoma may be difficult to distinguish from the dominant nodule of a multinodular goitre. Occasionally, it has some dependence on TSH and can be made to regress by administering thyroid hormones.

Other benign tumours of the thyroid are rare e.g. lipomas, haemangiomas and dermoid cysts.