Thyroid cancer is the most common endocrine malignancy and can be classified into four types according to the pathological type, namely papillary, follicular, undifferentiated and medullary carcinoma. In most cases, the early presentation is an isolated solid nodule in the anterior neck area, which is painless and can move up and down with swallowing. It may persist for a long time and develop slowly, or it may increase significantly in size in a short period of time. Among the various types of thyroid cancer, papillary carcinoma is the most common type of thyroid cancer, mostly seen in young people, and is usually a solitary lesion. Some patients present with enlarged lymph nodes in the neck and the swelling in the thyroid gland may have been there for months or years. Because of its slow development and lack of specific signs, it is often misdiagnosed as benign and the swelling can be small. Undifferentiated carcinoma is common in the elderly, with a low incidence and high malignancy. Its disease develops faster and grows rapidly after the appearance of neck swelling, which is fixed within 1-2 weeks, with hoarseness and difficulty in breathing. In contrast, medullary carcinoma is mainly a lump in the thyroid area, sometimes with enlarged lymph nodes, and early cervical lymph node metastasis may appear. However, most of them grow slowly, and the course of the disease can be as long as 10-20 years. Medullary carcinoma is often familial and may have its characteristic symptoms, such as diarrhea, palpitations, facial flushing and decreased blood calcium. When a single nodule in the thyroid gland is found on palpation, with firm texture and clear boundaries compared with surrounding tissues, the possibility of thyroid cancer should be considered.