Thyroid nodules larger than 1 cm in diameter showing no signs of growth

Can a thyroid nodule >1 cm in diameter be considered benign if it does not show signs of growth on repeated ultrasonography?

Leonard Wartofsky, MD: No, a nodule cannot be considered benign based simply on its growth patterns. One would need to have a proof of benignancy based on fine-needle aspiration cytology, mutational analysis, and so forth.

Thyroid cancer grows very slowly and may be present for years, sometimes decades, with minimal detectable growth until, at some time, there may be subsequent mutations that are more aggressive, grow more rapidly, and signal the malignancy. But slow growth alone would not rule out cancer.