What causes toxic adenoma?

Updated: Oct 19, 2020
  • Author: Stephanie L Lee, MD, PhD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
  • Print

Toxic adenoma is caused by a single hyperfunctioning follicular thyroid adenoma. This disorder accounts for approximately 3-5% of thyrotoxicosis cases. The excess secretion of thyroid hormone occurs from a benign monoclonal tumor that usually is larger than 2.5 cm in diameter. The excess thyroid hormone suppresses TSH levels. RAIU usually is normal, and the radioactive iodine scan shows only the hot nodule, with the remainder of the normal thyroid gland suppressed because the TSH level is low.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!