According to experts who presented at the May, 2002 annual meeting of the American Association of Clinical Endocrinologists, among benign thyroid nodules, only a quarter show any sign of growing at all. Among those that do grow, they grow so slowly that five years need to pass before the growth can even be detected with sensitive ultrasound. These findings lead the researchers to conclude that annual ultrasound scans are not needed for patients with benign thyroid nodules.

Thyroid nodules are present in as many as 30 percent to 50 percent of the population, and can actually be felt in 4 percent to 7 percent of the population. Less than 5 percent of nodules are malignant. Non-malignant nodules typically are not treated, unless they cause hyperthyroid symptoms, or are growing.

Source: American Association of Clinical Endocrinologists – May 2002 Proceedings