What tests should be done for thyroid cancer? Ultrasound is preferred for thyroid cancer, and there are some other tests that your doctor will choose based on your condition. Commonly used tests are as follows: (1) Thyroid isotope scan. Because thyroid cancer tissue generally lacks affinity for radioisotopes, thyroid scan can be performed with 131Ⅰ or 99mTC, and cancer is mostly cold nodules, which is not a special diagnostic method, because thyroid cysts, abscesses and adenomas can also be cold nodules and should be combined with other conditions for diagnosis. (2) Serum thyroglobulin. The level of thyroglobulin has nothing to do with the benignity or malignancy of thyroid tumors. However, it can detect the recurrence of tumor. If the serum thyroglobulin is increased after total thyroidectomy, it indicates cancer recurrence. (3) Ultrasonography: Ultrasonography is preferred for thyroid cancer. The following features suggest thyroid cancer: (1) solid hypoechoic nodules; (2) rich blood supply in the nodules; (3) irregular nodule shape and margin, halo absence; (4) microcalcifications, pinpoint-like diffuse distribution or clustered calcifications; (5) simultaneous abnormal ultrasound images of cervical lymph nodes, such as round lymph nodes, irregular or blurred borders, uneven internal echogenicity, calcifications, dermal medulla, and dermatomes. (4) CT, nuclear imaging, and cystic changes. (4) CT and MRI are generally not required. If the relationship between vascular nerve and cancer tissue needs to be evaluated during surgery, enhanced CT examination can be performed. (5) Puncture biopsy. For those who do not want to have surgery, fine needle aspiration cytology pathology examination can be considered to exclude malignant nodules. (6) Pathological examination of surgical excision. Intraoperative frozen section pathology examination is currently second only to paraffin section pathology examination in terms of accuracy. The results of frozen section pathology examination will be available in half an hour to know whether the tumor is benign or malignant. Post-operative paraffin sections are usually reported in 3-5 days.