Guest Author - Jim Lowrance
Thyroid nodules are small tumor-like growths on the thyroid gland. According to statistics, as much as 10 percent of the population has thyroid nodules but they occur far more often in thyroid diseases. People with autoimmune thyroid diseases have abnormal thyroid tissue and over time can develop a large number of nodules or what is referred to as “multi-nodules”.
Thyroid nodules can be detected by feel or “palpation” but some may be in an area of the gland that are only detectable by diagnostic imaging tests such as “thyroid ultrasound” (sound wave imaging), “Radio Active Iodine Uptake Scans” (radiological imaging) and “MRI” (Magnetic Resonance Imaging).
Thyroid nodules that are solitary or found to be a single one, have a slightly higher risk of containing cancer cells (malignancy) than do multi-nodules and larger nodules are also considered more suspicious. When a solitary nodule is located, the treating Doctor may wish to have a tissue biopsy performed. The procedure that is usually performed to obtain a thyroid nodule tissue sample is called a “Fine Needle Aspiration” (FNA) and is a simple out-patient procedure. The tissue sample is then lab-analyzed to detect any abnormal cells indicating the presence of either “papillary” or “follicular” cancer, which are the two major types that can potentially invade the thyroid gland. Fortunately, should cancer cells be detected, thyroid cancers have a very high treatment success rate. Treatment of benign thyroid nodules involves removal of the thyroid gland (total thyroidectomy) and administering full thyroid hormone replacement therapy for that patient as a lifelong treatment.
When thyroid nodules are being investigated, they may be placed into several categories. We have already looked at solitary and multi-nodules but other terms used in describing them include “hot nodules”, meaning the nodule is actively absorbing iodine from the thyroid gland and is releasing thyroid hormone, causing a hormone imbalance in the patient (hyperthyroidism). Smaller hot nodules may not cause hyperthyroidism while larger ones usually do and many times are also biopsied due to their larger size. If the nodule is not causing thyroid hormone release, it is referred to as a “cold nodule” and both hot and cold nodules have a distinct appearance on diagnostic imaging tests.
Some thyroid nodules are more solid than others which are referred to as a “solid nodules” and these are also considered more suspicious of possibly containing cancer cells and may also be biopsied as a precaution, depending upon their size. Many non-solid nodules are considered to be “cystic nodules” because they will contain fluid in the center of them and these type, are almost never considered a risk for containing cancer cells.
While this gives us a basic understanding of most types of thyroid nodules and how they more commonly manifest, there are always the possibilities of crossover features. In other words, some are not as easily distinguishable as being one specific type and may have features of several types (complex nodule).
If you find that you have a growth/tumor or several growths on your thyroid gland, it is important that you see your Doctor for an evaluation of them. Your Doctor will likely thoroughly palpate your thyroid gland (feel by fingertips) and if he/she determines that the nodules need further evaluation, may also send you for a thyroid ultrasound or uptake scan. These will help determine whether there is a need to have any nodules biopsied, as a precaution against developing thyroid cancer.