Detecting Thyroid Nodules

Thyroid nodule which contains tiny calcifications and blood flow was proven to be cancer.

Kathy is a friend of mine who had a dilemma. During a routine physical exam, her doctor discovered a lump on her throat and was concerned that she had a thyroid nodule. Although this might be nothing serious, she was worried that it could be cancer. At the same time, she had no symptoms and felt fine. She could not feel the nodule herself. In fact, she was not even sure what the thyroid gland does. She immediately called me with many questions.

Q: What is the thyroid gland?
A: The thyroid gland is a butterfly-shaped gland located at the bottom of your throat, just above your collarbones. It produces hormones, which regulate your metabolism called T3 and T4. It also produces a hormone called calcitonin, which controls the amount of calcium in your blood and in your bones.

Q: How common are nodules on your thyroid?
A: Approximately 50 percent of the population has at least one thyroid nodule. Fortunately, over 90 percent of these are benign (not cancerous). Those that are cancer are very slow growing. The reason most people do not know they have a thyroid nodules are because most of these nodules do not cause symptoms. Rarely, larger nodules can cause jaw pain, difficulty swallowing, or difficulty breathing. Occasionally, a nodule can produce large amounts of thyroid hormone increasing your metabolism. This is called hyperthyroidism and can cause symptoms such as anxiety, irritability, heart palpitations, and difficulty sleeping.

Q: How are thyroid nodules diagnosed? How can you tell if they are cancerous?
A: Nodules larger than 1 cm can be detected by physical exam. The most common way thyroid nodules are diagnosed is by ultrasound. Ultrasound uses high frequency sound waves (much like sonar in submarines) to show the thyroid gland and to detect disease. Ultrasound is a great tool for diagnosis because it is relatively inexpensive, the tests are performed quickly, and it does not use radiation. In addition to detecting nodules, ultrasound can help determine the character of the nodule. Nodules, which cause suspicion of cancer, are made up of solid tissue (as opposed to being entirely filled with fluid), are larger than 1 cm, have internal blood flow, and have microcalcifications. Ultrasounds are ideal to characterize thyroid nodules and predict, which is more likely cancer and which are more likely benign.

The definitive way to detect cancer is a biopsy. A biopsy is removing a small piece of tissue and examining under a microscope. Most biopsies are performed using an ultrasound for guidance. If a nodule is determined to be cancerous or the nodule is causing symptoms such a hyperthyroidism, it is removed by a skilled surgeon.

Q: If a thyroid nodule is not determined to be cancerous, what then?
A: Most thyroid nodules are followed by ultrasound once a year to be sure they remain stable. If a nodule increases in size develops microcalcifications, or has increased bloodflow, there is a fear that nodule is becoming cancerous. At that time, a repeat biopsy may be performed.

Kathy had an ultrasound that showed a 1.5 cm solid nodule. The good news is a thyroid biopsy showed her nodule was not cancer. Kathy followed up with her doctors, had her annual thyroid ultrasound and she feels very confident she is in good hands.