A lump on top of the breast is called a breast lump, which may be benign or malignant, and requires a physical examination and then a breast ultrasound or mammogram. If necessary, breast ultrasound should be performed to observe the echogenicity, texture, boundary, and the presence of calcification or abnormal blood flow signals of the breast nodule. Routinely, breast nodules can be graded, with grades 1-3 indicating benign and grades 5-6 indicating malignant. If the mass is considered to be malignant, which means breast cancer, modified radical breast cancer surgery is required. If the mass is considered to be benign, fibroadenoma of the breast is the main cause. For small masses, the patient can be followed up, but if the mass is large and has pressure, or affects aesthetics or causes pain, surgery is also needed.