Thyroid Cancer Symptoms and Diagnosis

A lump in the neck, and neck swelling, are often the first signs of thyroid cancer.

Thyroid cancer affects the thyroid gland, which is located in the neck and releases hormones that help regulate metabolism, growth, and maturation.

This cancer can often be detected — and treated — early because it produces conspicuous signs and symptoms that people notice and then ask their doctors to examine.

Thyroid cancer is sometimes found during a routine checkup. It may also be found in an ultrasound, a CT scan, in blood tests, or via other procedures conducted for different health issues.

Signs and Symptoms of Thyroid Cancer

A lump in the neck, which may grow quickly, is a common sign of thyroid cancer.

Other symptoms of thyroid cancer can include:

• Neck swelling
• Cough that is not due to a cold or other issue
• Difficulty swallowing
• Difficulty breathing
• Pain in the front of the neck, which may extend up to the ears
• Hoarseness or voice changes

In some cases, thyroid cancer doesn't produce any initial symptoms.

However, symptoms will develop as the tumor grows larger.

It's also important to note that other conditions may cause symptoms similar to thyroid cancer.

Detecting Thyroid Cancer

As with other types of cancer, diagnosing thyroid cancer begins with your doctor’s review of your symptoms and medical history, including a family history that may indicate a higher risk of getting thyroid cancer.

Your doctor will also perform a physical exam, paying special attention to the feel and size of your thyroid and the lymph nodes in your neck, where the cancer might have spread.

If thyroid cancer is suspected, your doctor or a specialist may order various tests, which can include:

• Laryngoscopy, which involves inserting a thin fiber-optic instrument into the throat to see if a tumor is pressing on the vocal cords
• A neck ultrasound, which can determine if a thyroid nodule or lump is fluid-filled or solid (solid nodules are more likely to be cancerous)
• Computed tomography (CT) scans, which can help determine the location and size of thyroid cancers using cross-sectional X-ray images
• Magnetic resonance imaging (MRI), which can provide highly-detailed images of the thyroid
• Positron emission tomography (PET) scans, which can look for the spread of thyroid cancer in all areas of the body at once (usually performed after cancer is diagnosed)
• Blood tests that measure the levels of certain hormones — particularly thyroid-stimulating hormone (TSH), T3, and T4 — to see how well the thyroid is functioning
• Blood tests that look for cancer markers, such as elevated levels of calcitonin (a hormone produced by thyroid "C" cells), which can indicate a type of thyroid cancer called medullary carcinoma

Thyroid Cancer Diagnosis

An actual diagnosis of thyroid cancer can only happen following a biopsy, a procedure in which doctors remove cells and study them under a microscope.

In a fine-needle aspiration biopsy, a specialist will insert a needle through your skin and into your thyroid several times to take tissue samples from different areas of the gland.

A surgical biopsy — a more invasive procedure — may be necessary if results from a fine-needle aspiration biopsy are unclear.

This surgery may involve using a larger needle to suck out a large amount of a tissue, known as a core biopsy, or cutting into the neck to reach the thyroid, known as an open biopsy.

In an open biopsy, your doctor may remove a thyroid nodule or an entire thyroid lobe (the thyroid has two lobes, connected by a strip of tissue).