Thyroid nodule is a mass inside your thyroid gland. Usually a physician discovers it during a routine physical examination. Although a patient may sometimes notice a lump in their thyroid area in the neck and seek medical advice.
On other occasions, a CT scan of your neck or chest done of some other reason may incidentally discover a nodule in the thyroid gland.
Thyroid Nodule Symptoms
Most thyroid nodules do not cause any symptoms. Occasionally, a patient may feel pressure in the thyroid area if a nodule is large in size. Only rarely, a cancerous nodule may extend beyond the thyroid gland. It may extend into the lymph nodes in the neck or may travel to distant organs such as lungs, bones and brain.
Benign Versus Cancerous
The biggest concern with a thyroid nodule is whether it is cancerous or benign.
Most thyroid nodules (more than 95%) are not cancerous.
However, a thyroid cancer may rarely be present.
Factors that increase the likelihood of thyroid cancer are:
1. Older age.
2. Large size of the nodule and its morphologic features on Thyroid Ultrasound.
3. Family history of thyroid cancer.
4. History of exposure to radiation to the head and neck area.
5. History of exposure to a nuclear reactor disaster; atomic bomb survivors.
Diagnostic Testing of a Thyroid Nodule
A blood test for thyroid function should be carried out first. This test is normal in most cases and further testing will be necessary.
Occasionally, the thyroid function test may indicate that a person is hyperthyroid (overactive thyroid). In these cases, chances of thyroid cancer are extremely low.
An ultrasound guided Fine Needle Aspiration (FNA) Biopsy is the most practical way to evaluate a thyroid nodule.
The results of FNA are reported as one of the follows:
- Negative for malignancy or benign.
- Positive for malignancy, probable papillary thyroid cancer.
- Follicular neoplasm which may be cancerous or benign.
- Indeterminate, which means the pathologist could not determine whether it is benign or cancerous. Often, this situation arises if the specimen is inadequate. Most endocrinologists would recommend to repeat the FNA biopsy.
The result of the FNA biopsy pretty much dictates what further treatment you need.
Most endocrinologists would recommend a follow-up thyroid ultrasound in a year if the FNA biopsy report is negative for malignancy.
On the other hand, they would recommend thyroid surgery if the FNA report is positive for malignancy. In addition to surgery, you will also need further treatment and follow-up in case of a thyroid cancer.
For follicular neoplasm, your endocrinologist will decide whether to recommend surgery, repeat the FNA biopsy or a careful observation with a repeat thyroid ultrasound in 6-months period.
If the FNA report is indeterminate, your endocrinologist would most likely recommend a repeat FNA biopsy.