Thyroid Nodules: Sorting The Wheat From The Chaff

 

Thyroid nodules are a common problem in the primary care setting. Even though the incidence of malignancy remains low at around 10%, nodules are still a cause of anxiety for patients, especially in cases that are symptomatic or enlarging. Timely referral to the specialist surgical clinic enables the nodules to be investigated and treated promptly. 

How do thyroid nodules present?

Thyroid nodule cases are frequently referred to the Head and Neck Surgery clinic, under the General Surgery Department in Tan Tock Seng Hospital (TTSH). It is estimated that up to 60% of the population may harbour thyroid nodules.

While a majority of nodules are small, asymptomatic and never noticed; others may present as a lump in the anterior neck as a first symptom. While painless, the patient may be alarmed by an increasing growth or onset of compressive symptoms such as difficulty in swallowing. Rapid growth of the nodule may cause pain in some cases.

Young and educated patients are among those concerned about the risk of malignancy. Given the prevalence, many patients are also aware of family or friends who have had similar problems or have undergone previous surgery.

Making the right diagnosis

After an adequate examination, the workup for thyroid nodules should include an ultrasound and fine-needle biopsy. Blood tests to determine the thyroid function may be done to screen for concomitant hyper- or hypothyroidism.

Since an examination is insufficient to differentiate solid from cystic nodules as well as to screen for other non-palpable nodules or lymph nodes, an ultrasound is recommended. The ultrasound is accurate in picking up features that immediately raise the suspicion of malignancy. This can then be followed by an ultrasound-guided fine-needle biopsy of the nodule(s). Such targeted biopsy increases the yield of cytology by up to 75%.

In our practice at TTSH’s General Surgery Department, a one-stop service is provided such that all these investigations are performed within the clinic upon initial consultation. This serves to greatly allay the patient’s fears and anxieties as the cytology result is often available the next day.

For patients with large cystic nodules, complete aspiration via ultrasound guidance provides immediate relief and assurance. When thyroid malignancy is suspected, further imaging of the neck for invasion or metastasis using Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI) may be obtained within a short notice. Nowadays, a radionuclide thyroid scan has very limited utility.

 

Which treatment is suitable for the patient?

When the thyroid cytology report is available, patients are counselled based on the National Cancer Institute (Bethesda classification) recommendations. A benign result brings reassurance and relief.

The patient may then opt for a conservative approach with regular follow-ups and surveillance ultrasound with the referring primary care physician.

A cytology result that is malignant or suspicious would warrant total thyroidectomy, often performed with nodal dissection. The remaining categories of cytology require further discussions with the patient. Surgery may eventually be necessary to ascertain the histology accurately. Some patients with large, benign nodules may still opt for surgery because of fear of a falsenegative result, persisting symptoms or for cosmetic reasons.

Traditional open surgery with a cosmetic-centric and minimalscar approach is the standard recommendation. For patients keen to avoid a neck scar, endoscopic and robotic thyroidectomy are available. Both surgical approaches allow the thyroid to be resected via incisions that are sited away from the neck such as in the chest and axilla.

 


 

Dr. Ho Wai Thong, Thomas 

Dr. Thomas Ho is the Head and Consultant of the Head and Neck Surgical Service under the Department of General Surgery at Tan Tock Seng Hospital, Singapore. Dr Ho has completed a Surgical Oncology Fellowship in Canada. His areas of interest include treatment of head and neck, colorectal and advanced pelvic cancers.