Thyroid cysts can potentially become cancerous. Initially, thyroid cysts may arise from various thyroid diseases such as nodular goiter, Hashimoto's disease, thyroid adenoma, and thyroid follicular cancer, which form through degeneration, liquefaction, and hemorrhage. They are one of the common diseases of the thyroid. In the population, at least 4% of people can feel thyroid nodules larger than one centimeter. Among these nodules, about 5% to 20% are cystic. Statistics show that even benign lesions causing cysts have a 4%-5% chance of becoming cancerous when the diameter of the individual exceeds 4 centimeters. Therefore, thyroid cysts can potentially become cancerous.