Thyroid nodule evaluation and diagnosis
Thyroid nodules are usually benign(non-cancerous) but in some cases they may contain cancerous cells. In order to determine whether these nodules need to be removed or not, they require some kind of evaluation.
Most thyroid nodules do not cause any symptoms. Often, nodules present as a lump in the neck and patients notice them when looking in the mirror or are told of their presence by a friend or family member. Uncommonly, a large nodule may cause difficulty in swallowing, breathing or hoarseness of the voice.
Once the nodule is discovered, the doctor will have to assess whether it is cancerous or not. Moreover, the general condition of your thyroid has to be evaluated by performing a series of examinations, such as:
- Thyroid Function Tests, are blood tests which measure the levels of thyroid hormones in the blood stream. They are used to determine if your thyroid gland is functioning normally or is overactive.
- Thyroid Ultrasound is a key examination in the investigation of a thyroid nodule. Ultrasound can very accurately evaluate the presence of a single or multiple nodules, measure the size and define any special characteristics that render the nodule suspicious for cancer or completely benign, e.g. echogenicity, presence of calcifications, solid or cystic content etc.
- Fine needle Aspiration Biopsy (FNAB) is a simple procedure and can be done at the doctor’s office. Under local anesthetic and under US guidance, the doctor inserts a fine needle through the patient’s skin and into the thyroid nodule in order to aspirate some cells. These cells are then examined under a microscope by a pathologist.
FNA results are usually the following:
- Nodule is benign(non-cancerous), result obtained in more than 80% of cases.
- Nodule is cancerous or suspicious for malignancy, obtained in about 5% of cases and is most often due to papillary cancer.
- Nodule is indeterminate, meaning that the nodule is described as a follicular lesion. Follicular lesions are usually benign but can herald cancer in up to 20-30% of cases. Complete and safe diagnosis can only be made by surgery.
- Biopsy may be inadequate or non-diagnostic. This means that not enough cells were aspirated during the biopsy and it needs to be repeated.