Thyroid 4c usually refers to a grade 4c in the TI-RADS classification of a thyroid mass, which requires surgery if diagnosed as malignant, not all of which must be operated on. The TI-RADS classification is a clinical method used to describe the degree of malignancy of a goiter. If a goiter has a TI-RADS classification of 4c, the probability of malignancy of the mass is 50-90%. If the thyroid mass reaches grade 4c, thyroid puncture pathology can be performed to further define the benign or malignant nature of the tissue; if malignant, surgery is needed as soon as possible; if benign, thyroid ultrasonography needs to be repeated regularly for regular follow-up and observation. If the thyroid mass is grade 4c, you need to go to the hospital in time, combine with your own condition, and standardize the treatment under the guidance of the doctor.