A stage IV thyroid nodule should be a thyroid nodule ultrasound suggestive of a TI-RADS classification of 4 or higher. This is generally divided into 4a, 4b and 4c, and is mainly judged by the morphology and borders of the thyroid nodule, whether it is growing in an upright manner, and whether there is any punctate or sandy calcification and blood flow. In this case, we cannot exclude the possibility of thyroid cancer and suggest a fine needle aspiration for further clarification. If it is not urgent in the thyroid parenchyma, if it is closer to the peritoneum, it is recommended to go for these examinations as soon as possible. Because of the possibility of invasion of the surrounding trachea, esophagus, blood vessels, nerves, etc., it is important to seek prompt medical attention. If the puncture suggests bad or BRAF gene is mutated, this kind of thyroid nodule is recommended to be treated surgically and not to be easily treated by microwave ablation.