Thyroid Cancer Symptoms and Diagnosis
Early thyroid cancer may not cause any symptoms. As a tumor grows slowly overtime, it may lead to the following symptoms:
A lump in the neck
A lump in the neck is the most common early sign of thyroid cancer. If you notice a swelling or lump at the front of your neck, see your GP immediately. While it’s unlikely to be cancer, it’s important to get it checked out.
Swollen lymph node
Swollen lymph nodes in the neck are another symptom of thyroid cancer. Thyroid cancer can spread to the lymph nodes, which are scattered throughout your body to help you fight infection. When the infection is gone, they should return to their normal size, so if the lymph nodes in your neck stay enlarged for an extended period and you aren’t sick, you should talk to your doctor.
The thyroid is on top of your trachea so a developing thyroid cancer may put pressure on your trachea, causing difficult breathing. This is an uncommon way that thyroid cancer is detected.
Since your thyroid gland locates just below the larynx (voice box). A thyroid nodule, either benign or malignant in origin, may be pressing on the voice box, causing hoarseness or voice changes. This is also an uncommon way that thyroid cancer is detected.
Thyroid cancer is a rare cause of neck pain but if you have persistent neck pain combined with some of these other symptoms, be sure to talk with your doctor.
How Thyroid Cancer is Diagnosed?
To diagnose thyroid cancer, your GP will examine your neck and ask about any symptoms you may be experiencing. If they think you might have a thyroid problem, they may arrange some tests to help identify the underlying cause.
Your doctor will do a blood test to check the levels of T3, T4 and Thyroid-Stimulating Hormone (TSH). A cancerous thyroid can continue to function normally so a blood test may help rule out benign thyroid conditions such as hyperthyroidism or hypothyroidism.
If your doctor suspects you have medullary thyroid cancer, the levels of calcitonin may also be checked because high calcitonin levels in the blood can be a sign of medullary thyroid cancer.
An ultrasound is a type of scan that uses sound waves to create an image of the inside of your body. The scan can show:
- The size of the thyroid nodule, including whether it is full of fluid or solid.
- Whether a nodule has any characteristics that suggest it may be a thyroid cancer.
- Whether the lymph nodes in the neck are affected or not.
The ultrasound scan is painless and only takes about 15 to 20 minutes. During the procedure, a gel is spread over your neck then a handheld device called a transducer is moved over the area. This creates a picture of the internal structure of your thyroid on a computer monitor. If a potentially cancerous lump is found, a biopsy will be carried out to confirm the diagnosis.
A biopsy is the removal of a small amount of tissue for examination under a microscope. This is usually done using a thin needle inserted into the lump. An ultrasound scan may be carried out at the same time to ensure the needle goes into the right place.
If your doctor thinks a biopsy is needed, the simplest way to find out if a thyroid lump or nodule is cancerous is with a Fine Needle Aspiration (FNA) of the thyroid nodule. This type of biopsy can sometimes be done in your doctor’s office or clinic.
Before the biopsy, local anesthesia (numbing medicine) may be injected into the skin over the nodule, but in most cases an anesthetic is not needed. Your doctor will place a thin, hollow needle directly into the nodule to take out some cells and a few drops of fluid into a syringe. The doctor usually repeats these two or three times, taking samples from several areas of the nodule. The biopsy samples are then sent to a lab, where they are looked at to see if the cells look cancerous or benign.
The following scans are sometimes used to see if the cancer has spread from the thyroid gland to other parts of your body. This process is called staging. Some scans may be repeated after treatment to see how well the treatment has worked.
A CT (Computed Tomography) scan uses x-ray beams to create a detailed three-dimensional picture of the inside of the body. It can help determine the location and size of thyroid cancers and whether they have spread to nearby areas, although ultrasound is usually the test of choice. A CT scan can also be used to look for spread into distant organs such as the lungs.
One problem using CT scans is that the CT contrast dye contains iodine, which interferes with radioiodine scans. For this reason, many doctors prefer MRI scans for differentiated thyroid cancer.
Similar to CT scans, a MRI (Magnetic Resonance Imaging) can create detailed cross-sectional images of your body. It can be used to look for cancer in the thyroid, or cancer that has spread to nearby or distant parts of the body. MRI scans are also very helpful in looking at the brain and spinal cord.
A PET (Positron Emission Tomography) scan is a nuclear imaging technique that creates detailed, computerized pictures of organs and tissues inside the body. PET scans are very sensitive, but they do not show much detail, so they will often be performed in combination with a CT scan called a PET-CT scan.
A PET scan is rarely needed for thyroid cancer. However, it may be useful in some types of thyroid cancer, particularly if other tests give conflicting results.