Subcutaneous breast cysts are commonly seen as breast cysts and sebaceous breast cysts. 1. Breast cysts: a relatively common disease in women, mainly manifested as a subcutaneous lump in the breast, the lump is relatively soft or tough, the mobility is relatively poor, most of them are round or oval, basically there is no pain when touching them, and some of the breast cysts will also change in size along with menstruation cycle, which can be diagnosed through the ultrasound examination of the mammary glands. 2. Breast sebaceous cysts: subcutaneous lumps of different sizes, mostly single, occasionally multiple, mostly round, hard or elastic, normal skin color, smooth surface, no fluctuating feeling, the surface is often adhered to the skin, but the base can be movable. The center of the cyst often has a black pinpoint-sized depression, and white contents can be overflowed when pressed, sometimes accompanied by a bad smell. It is recommended to consult the hospital and standardize the examination and treatment.