What exactly is a thyroid nodule and is it related to thyroid cancer? A thyroid nodule is not a disease, but a medical description of a lump found in the thyroid gland. There are benign and malignant thyroid nodules. Benign nodules include nodular goiter and thyroid adenoma, while malignant nodules are mainly thyroid cancer. Thyroid nodules are very common and more than 90% of them are benign, so there is no need to worry about most of them. However, the incidence of thyroid cancer has been increasing year by year in recent years, so it is necessary to have a thyroid ultrasound examination every six months.