THE thyroid gland is a butterfly-shaped organ perched on top of the trachea (windpipe).
It produces hormones that control the body’s metabolic processes, but if too much thyroid hormone is produced, it results in hyperthyroidism.
Inversely, insufficient thyroid production causes hypothyroidism. Generally, patients come to the hospital complaining about neck swelling, which is usually first spotted by friends or family.
Thyroid disease can be quite complicated as there is a wide range of symptoms. These can be categorised into three groups.
The first is hyperthyroidism, where too much thyroid hormone will speed up body metabolism and cause symptoms such as weight loss, insomnia, hand tremors, heat intolerance, diarrhoea, oily hair, irritability and palpitations.
The second, hypothyroidism, will cause symptoms such as drowsiness, lethargy, weight gain, cold intolerance, constipation and dry hair. Both disorders normally can be managed with medications.
The third category is thyroid tumour. While neck swelling could be caused by general swelling of the thyroid glands without a specific mass, the tumour means there is a definite growth out of the thyroid glands. It could be palpable by hand or only obviously seen under a scan.
Most patients are taken aback when they are told they have a thyroid tumour. However, most thyroid tumours are benign (non-cancerous).
While the presence of hyperthyroidism and hypothyroidism can be confirmed through a thyroid function blood test, thyroid tumours don’t normally affect thyroid hormone levels.
The more common term for thyroid tumour is thyroid nodule. The causes of thyroid nodule are unknown, but they are extremely common. By age 60, half of all people may have thyroid nodule.
Thyroid nodule is detected either by physical examination or by incidental finding through scans.
Once a thyroid nodule is detected, the patient’s blood will be tested to check his thyroid hormone level to determine if
the nodule is functioning and causing hyperthyroidism.
When a thyroid nodule is discovered, the doctor will need to arrange tests to further confirm the nature of the mass.
An ultrasound is performed, followed by fine-needle aspiration (FNA). FNA is a process where a tiny needle is inserted into the thyroid nodule to extract samples, which are sent for further study under a microscope.
If the FNA result proves that it is cancer, the patient will be advised to undergo thyroid removal.
However, there are some instances in which removal surgery is necessary, even if the FNA result is negative.
One of them is if the result is suspicious or indeterminate even though the sample is adequate for study.
If not enough cells are obtained for study, a second FNA could be performed.
Surgery is still advisable if the doctor feels the nodule is suspicious.
In some conditions, though the nodule is deemed benign via FNA and ultrasound, surgery is still suggested if the patient is suffering from symptoms such as choking or difficulty swallowing.
Patients can also opt for surgery for cosmetic reasons. Those with benign FNA results or have nodules too small for FNA should follow up with their doctors every six to 12 months for close monitoring.
Dr Lee Ching Hong is a consultant general surgeon at Ara Damansara Medical Centre.