Introduction :
About 68% of the general population have thyroid nodules on routine ultrasonography. That does not mean all nodules should be treated by surgery, as most nodules are benign and discovered incidentally. Therefore, the primary goal of thyroid nodule evaluation is to determine whether the nodule is malignant.
After thyroid ultrasonography has been performed, the next step is measurement of serum thyroid-stimulating hormone. Hyperfunctioning nodules are rarely malignant and do not require tissue sampling.
Nonfunctioning nodules and nodules in patients with normal or high thyroid-stimulating hormone levels may require fine-needle aspiration based on ultrasound characteristics and size. Nodules with suspicious features and solid hypoechoic nodules 1 cm or larger require aspiration.
The Bethesda System (categories I through VI) is used for classification. Benign nodules (Bethesda II) do not require surgery and should be followed up with regular physical examination and ultrasonography to monitor progression of the nodules, such as increase in size or suspicious changes, usually at one-year intervals.
As surgery is not without risk, unnecessary surgical intervention may lead to recurrent and superior laryngeal nerve damage, voice loss, parathyroid insufficiency, neck scarring, and lifelong thyroid hormone replacement.
In the UK, there is variation in monitoring thyroid nodules. Some hospital clinics discharge patients once cancer has been excluded, whereas other hospitals monitor nodules with repeat ultrasonography.
In Ireland, including our hospital, benign nodules are monitored with repeat ultrasonography at one-year intervals, a practice known as surveillance ultrasonography.