Cyst: Cystic tumor with inflammation, the size of which is more than 1CM, is hemispherical. The texture of the eruption is soft, and sometimes it is fluctuating and painful. The cyst evolves from deep pustules or nodules, forming a large cyst cavity in the dermis. If the undulator is cut open, white cheese-like substance and pus will flow out, and the cyst will shrink, but it can still recur because of the residual cyst wall. Cysts have a long course of disease, which can not heal for a long time. In the course of disease, secondary infections can also penetrate each other. At this time, because of the difficulty in treatment, the cysts leave scars after healing. Treatment: Open operation and drainage-minor operation, that is, cut the epidermis of the cyst mass, and then take out the cyst (even the cyst wall) with a racket. Some will also puncture the cyst wall to extract pus, and then take out the whole cyst wall, but it must be taken out completely, otherwise it is likely to recur. After that, the inflammation can be reduced for several days. The disease doesn't seem to be serious for the time being, but if the cyst wall breaks under the epidermis, it is likely to spread, so it is recommended to cure it in time. There will be scars after the operation.