The thyroid is a butterfly-shaped gland located in the front of the neck. It produces hormones that control metabolism in the body. The thyroid gland can sometimes develop solid or fluid-filled lumps (cysts). These lumps often do not cause symptoms and many of them are found incidentally during a medical consultation for another problem or during routine check-ups.
Although most of these lumps are not cancerous lumps, a small proportion of them will be cancerous. Some of these lumps may also cause problems when they grow larger and compress on other structures in the neck causing swallowing and breathing difficulties. Some of these lumps may also secrete too much thyroid hormone that may cause symptoms of hyperthyroidism.
1. Thyroid function tests
This is a blood test where the levels of your thyroid hormones (T4) and thyroid-stimulating hormone (TSH) are measured. If your levels of thyroid hormones are too high (hyperthyroidism), you may experience symptoms such as palpitations, feeling hot easily, irritability, diarrhoea, weight loss and increased appetite.
If your thyroid hormone levels are too low (hypothyroidism) you may feel easily tired and lethargic, gain weight easily, constipation, memory loss and feeling cold easily.
Thyroid-related diseases cannot be excluded even if the thyroid function test is within normal ranges.
2. Ultrasound Scan
In this scan, sound waves are used to produce a picture of your thyroid gland and neck structures on a screen. The ultrasound scan is very useful for evaluating thyroid nodules and to look for features that may indicate that the thyroid nodule is suspicious for cancer. It is also useful for looking for any enlarged lymph nodes in the neck. This scan is painless and there is no ionising radiation involved.
3. Fine-needle Aspiration Cytology (FNAC)
Your doctor may advise you to undergo a biopsy to evaluate the lump if he feels that it is needed.
A fine-needle aspiration biopsy is a procedure where the doctor will pass a small needle through the lump to aspirate some cells for the lump for further testing. These cells will be examined under a microscope to look for signs of cancer.
This biopsy is often done using an ultrasound to guide the doctor to biopsy the correct place.
If the results of the ultrasound and fine-needle aspiration show that the thyroid nodule is unlikely to be cancer, your doctor may choose to observe the lump and repeat an ultrasound scan 6-12 months later to look for any growth or changes in the lump.
However if there is a chance the lump may be a cancerous lump, or the lump is causing symptoms, your doctor may advise you for surgery. Surgery will usually involve removal of the thyroid gland (thyroidectomy).
Some thyroid cancers can spread to the lymph nodes in the neck and your doctor may need to remove some of the lymph nodes in your neck during the operation as well.