Most of the undifferentiated thyroid cancer is diagnosed through surgery, that is, after surgery, the patient is able to undergo a routine medical examination to tell us that the patient is an undifferentiated thyroid cancer. Of course, there are a few patients who can be diagnosed by puncture before surgery. After diagnosis, these patients will have a whole body examination because undifferentiated thyroid cancer is prone to distant metastasis, local infiltration growth, lung metastasis and bone metastasis are very common.