Thyroid Nodules - Diagnosis

Physical examination During a physical examination, your physician will often begin by looking at a your neck to see if it appears swollen or lumpy. By gently pressing his or her fingers along your neck, he or she can sometimes feel a thyroid nodule and determine its size, as well as evaluate the texture of the entire thyroid gland. In order to determine if your thyroid nodule moves or stays in one place, your doctor may ask you to swallow several times to observe or feel the movement of the thyroid gland and nodule. Laboratory tests Although laboratory tests cannot determine whether a nodule is cancerous, they are important for an accurate assessment of the thyroid gland. Tests that measure the amount of thyroid hormone and TSH in the bloodstream will indicate if your thyroid gland is functioning properly or if you are either hypo- or hyperthyroid. If you have a family history of thyroid cancer, your physician may order a test that measures the amount of calcitonin in your blood. High levels of this hormone are produced by medullary thyroid cancer, an uncommon form of thyroid cancer that can run in families. Fine needle aspiration biopsy The most important and definitive test to determine whether a thyroid nodule is cancerous is the fine needle aspiration biopsy. This is safe, relatively painless procedure that is usually done in an endocrinologist's, surgeon's, or pathologist's office. Your physician will insert a very thin needle into the thyroid nodule several times and withdraw thyroid cells and fluid into an attached syringe. These samples are sent to a cytology laboratory for analysis. You can receive one of the following four results: benign (not cancerous) unsatisfactory (not enough cells present) malignant (cancerous) inconclusive or suspicious (cells contained some features associated with cancer) Thyroid ultrasound Thyroid ultrasound cannot determine if thyroid nodules are cancerous or non-cancerous, but it can be a helpful diagnostic tool for identifying and measuring thyroid nodules as well as determining their structure. This is a painless procedure that forms a picture of the thyroid gland by bouncing sound waves off of it. Thyroid imaging with radioactive iodine Thyroid imaging will determine how your thyroid nodule is functioning. If your physician suggests this procedure, you may take either a liquid or pill containing a small amount of radioactive iodine, wait up to twenty-four hours, and return for imaging under a gamma camera. In hyperthyroid patients, a radioactive iodine uptake may be performed to determine how much iodine is "taken up” by a nodule and surrounding thyroid tissue. Hot nodules If your nodule takes up more of the radioactive substance than the surrounding thyroid tissue, it is called a hot nodule. Hot nodules can become overactive, causing hyperthyroidism, but they are seldom cancerous. Warm nodules If the thyroid nodule takes up the same amount of radioactive iodine as the surrounding tissue, it is called a warm nodule. Like hot nodules, warm nodules are rarely cancerous. Cold nodules If you have a nodule that takes up little or none of the radioactive iodine, it is called a cold nodule. Approximately 90% of thyroid nodules are cold; however, only 5% to 10% are cancerous. Normal Scan // Cold Nodule Hot Nodule Warning: Pregnant and nursing women should not have thyroid imaging or any procedure using radioactive substances.