Thyroid adenoma is a chronic lesion in the front of the neck that resembles a walnut and has a hard texture that can move up and down with swallowing. The initial stage of the disease usually has no obvious symptoms, but some of them may increase rapidly in size for a short period of time, and then continue to develop and affect breathing, and a few may develop hoarseness or difficulty in swallowing. Benign thyroid adenoma: Patients usually have no obvious symptoms. The mass is round or oval in shape, with no adhesion to surrounding tissues, and moves up and down with swallowing. The surface of the mass is smooth and the border is clear. Individuals with large masses may compress the trachea and displace the trachea and esophagus. Sometimes, due to bleeding in the mass, the tumor will suddenly increase in size, accompanied by local swelling and pain. Malignant thyroid adenoma: Patients often have discomfort such as swelling and pain in the neck and a sense of urgency. The lump is usually hard, irregular, with unclear borders and poor mobility. Some patients have swollen cervical lymph nodes in the early stage, which may cause hoarseness, difficulty in breathing and swallowing disorder. The obvious difference between benign thyroid tumor and malignant tumor: benign tumor has a certain limit in abnormal proliferation, and will not proliferate uncontrollably, and the speed of proliferation is relatively slow, and the damage to human body is relatively light, and the symptoms of compression of blood vessels and trachea may appear in heavy cases. On the other hand, malignant thyroid tumors, with faster cell division and proliferation, have obvious tendency to invade the surrounding tissues, and may even metastasize and endanger life.