Understanding thyroid nodules | What is thyroid nodules?

The thyroid gland is a butterfly-shaped and wraps around the windpipe just below the Adam’s apple. It produces thyroxine, a hormone essential for the normal function of many organ systems by careful regulation of cell metabolism. Normally, the thyroid gland cannot be seen or felt. Thyroid nodules refer to an abnormal growth that forms a lump on the thyroid gland, and are visible, moves with swallowing, or can be felt.

Dr Ranjiv Sivanandan, general surgeon at Mount Elizabeth Hospital, explains its significance.

Thyroid nodules are the most common presentation of thyroid cancer. While thyroid cancer itself is not common in Singapore, thyroid nodules are exceedingly prevalent. In addition, the incidence of thyroid cancer is increasing at 7% each year, growing faster than any other solid organ cancer. The greatest concern with thyroid nodules is that 1 in 20 is eventually diagnosed as thyroid cancer.

The presence of thyroid nodules
Thyroid nodules are very common, and detectable by clinical examination alone in 4%~7% of the general population. Advances in medical diagnostic imaging, however, have unearthed a much larger reservoir of ‘subclinical’ nodules. These nodules are smaller than 1cm, making it almost impossible to detect by normal means. Recent estimates are that 30% of women under 50 and 50% of women over 60 may have thyroid nodules that are detectable by ultrasound.

Most thyroid nodules, whether benign or malignant, appear as painless a central neck lump that moves with swallowing. Otherwise, they do not present any symptoms. Symptoms of difficulty in swallowing or breathing are sometimes seen in very large nodules or goitres. Dr Sivanandan recommends prompt assessment for possibility of thyroid cancer if a nodule is associated with voice hoarseness, rapidly growing, or found with other neck lumps.

Assessing thyroid nodules
The challenge in evaluating and managing thyroid nodules is accurately identifying the malignant and suspicious nodules from the vast majority of benign ones. Thankfully, this can be done with the help of two very important diagnostic investigations: thyroid ultrasound and a fine needle aspiration biopsy. Performed and read in experienced hands, these two investigations can help distinguish between benign and malignant nodules with 90%~95% accuracy.

Treatment for thyroid cancer
While most thyroid nodules are benign, those which are large, growing, or suspected of malignancy should be removed surgically. Conventional open thyroid surgery is safe and efficient. It is usually performed through a curved incision in the lower central neck. Female patients, especially the young and middle-aged, often ask if it is possible without a neck incision as it would leave a scar. For many years, the answer was ‘no’.

Advancing robotic technology, however, has changed that. It is now possible to remove a thyroid nodule without a visible or neck incision. The point of entry can instead be placed in the underarm, through which the thyroid nodule can be safely and completely removed. This procedure is called robotic thyroidectomy. According to Dr Sivanandan, patients who have undergone this procedure are extremely pleased with the result, because there are no visible signs of thyroid surgery at all.

Recovery from thyroid cancer
The good news about thyroid cancer is that it is not difficult to treat. Early diagnosis and treatment of thyroid cancers results in a cure rate of 98%~99%, a far better prognosis than any other solid organ cancer. In addition, most patients return to where they were in life without any long term cosmetic or functional impairments. It is like they have never had cancer at all.

Publication of article by courtesy of Dr Ranjiv Sivanandan, a general surgeon at Mount Elizabeth Hospital