In the case of breast cysts, the first option is non-surgical treatment with aspiration. If the milk-like fluid can be aspirated, the cyst should be aspirated at once, and when the milk is aspirated, the cyst shrinks immediately, and then pressure bandages are given, and in a few cases it can be cured by aspiration at once. If the cyst is recurrent and repeated punctures are ineffective or if the cyst is repeatedly infected with inflammation and keeps increasing in size, simple removal of the cyst can be performed under local anesthesia. If the cyst is benign, simple removal of the cyst is sufficient and it is not necessary to remove the entire mammary gland. If there is acute inflammation, anti-inflammatory treatment can be performed first before surgery.