In general, a solitary thyroid nodule is more likely to be malignant than a multiple nodule or nodular goiter. Patients should be alerted to the possibility of cancerous nodules if they present with the following: ① Single nodule in the thyroid gland in children under 14 years of age, of which 10% to 50% are malignant. (2) A single nodule in the thyroid gland in an adult male. ③A thyroid nodule that has existed for many years and has increased significantly in size in a short period of time. ④Patients living in coastal areas have a much higher chance of having a solitary nodule that is cancerous than patients from areas where endemic goiter is prevalent. ⑤ Patients who have received radiation therapy to the head and neck during childhood should be aware of a single nodule in the thyroid gland. (6) Physical examination should show hard nodules with irregular fixation or with ipsilateral neck lymph node enlargement, vocal cord paralysis, or hoarseness. (7) Neck radiograph shows calcified shadows in the thyroid gland in cloudy or granular shape. The border is irregular. The tracheal stenosis caused by thyroid cancer is often normal in left and right diameter, and anterior and posterior diameter can be normal. (8) Ultrasound examination shows solid or cystic solidity with uneven internal echogenicity, unclear and irregular borders, especially with sand granules, calcified foci and/or abundant or abnormal blood flow.