Thyroid Cancer

What is thyroid cancer?

Most of the nodules arising in the thyroid gland are benign and only about 5-10% of those getting medical attention are cancer. A nodule which is cold on scan is suspicious but the majority of cold nodules are benign.

When to suspect thyroid cancer?

• Thyroid nodule in a young < 20 years or old >70 years person.
• A sudden increase in the size of a thyroid nodule.
• Recent changes in voice, breathing or swallowing.
• Family history of thyroid cancer.

What are the tests done to diagnose thyroid cancer?

Laboratory investigations

Thyroid function tests are usually normal in the presence of a thyroid nodule and presence of hypo/hyperthyroidism favours a benign nodule.

Thyroglobulin levels are useful after thyroid gland is removed to diagnose metastasis.

Ultrasound of the neck

Guides fine needle biopsy when necessary

A mixed nodule (solid and cystic) is more suspicious of cancer.

There are certain features in ultrasound test that can raise suspicion of cancer.

FNAC (Fine needle aspiration cytology)

Needle is placed into the nodule and cells are aspirated into a syringe. The cells are placed on a microscope slide, stained, and examined by a pathologist. The nodule is then classified as nondiagnostic, benign, suspicious or malignant.

Isotope scan

Isotope scan mostly shows cancer nodule as cold but only a few of cold thyroid nodules are cancer.

What are the treatment options?

Surgery – Once diagnosed surgery is a must to remove the nodule/ entire thyroid gland. The lymph nodes in the neck are assessed to see if they need to be removed also.

About 4 weeks after the thyroid has been removed, the patient will undergo radioiodine treatment. The dose is around 20 times more of what we give for overactive thyroid.

Patients need to be isolated as there is a risk of radiation exposure to others with this dose. The pill will contain the radioiodine in the dose that has been calculated for that individual. This will destroy the thyroid cells those are left out after surgery.

After this we start on thyroid hormone.

What is the follow-up required?

1. Clinical follow up at frequent intervals is a must.
2. Thyroid function tests we do from time to time to see the amount of thyroid patient should take.
3. Thyroglobulin – A high serum thyroglobulin level that had previously been low following total thyroidectomy is virtually indicative of recurrence.