Cystic change means that the nodule is originally solid and has internal cystic fluid production, forming a cyst. Cystic changes indicate that the nodule is a benign lesion, and malignancy can be basically excluded. During physical examination, the nodule with cystic change changes from a hard texture to a soft texture with fluctuating sensation, and cystic fluid can be extracted during fine needle puncture, such as cystic change of nodular goiter or cystic change of thyroid adenoma or cystic change of breast hyperplasia. In cystic disease, the mass can suddenly increase in size, and sometimes there is bleeding inside the cyst and even pain. If the mass is very large and has symptoms of pressure, surgical removal can also be considered, and after removal, it is routinely sent for pathological examination.