Thyroid Nodule Diagnosis: The Basics

A physician performs an exam of you neck using his/her hands.

• Larger and more anteriorly (front) located nodules can be felt by the examiner.
  
• A physician will ask about any other medical history and any risk factors for thyroid nodules or cancer, including family history of thyroid cancer or radiation exposure of the head or neck.

Blood tests

• Thyroid stimulating hormone (TSH) levels and levels of thyroid hormone can indicate whether the thyroid is under- or overproducing thyroid hormones.
  
• Anti-thyroid antibody levels can indicate the presence of autoimmune thyroid inflammation that can be seen with Hashimoto's thyroiditis (underactive thyroid disease) or Graves's disease (overactive thyroid disease).
  
• Calcitonin levels in the blood can indicate a specific type of thyroid cancer, known as medullary carcinoma of the thyroid. However, calcitonin testing is generally not recommended as part of an initial evaluation of a thyroid nodule.

Ultrasound of the thyroid

This is a test that uses sound waves to take a picture of the thyroid. Similar to the prenatal ultrasound of the fetus, a cold lubricant jelly is placed on the neck; then, using an external probe, ultrasound images of the thyroid gland are obtained.

An ultrasound can reveal which thyroid nodules are larger than 1-1.5 centimeters, requiring further evaluation for cancer. In addition to size, other nodule characteristics that can be noted on a thyroid ultrasound include the following:

• number of nodules,
  
• location of nodules,
  
• distinctness of borders,
  
• fluid versus solid contents,
  
• other nodule contents, such as calcium deposits, or
  
• the amount of blood flow (certain newer ultrasound machines can assess blood flow to the thyroid and its nodules).