Breast lumps of oval shape with clear border and intact periphery, low and uneven internal echoes are the results of imaging examination, which may be caused by breast hyperplasia, breast cysts, mastitis and other diseases. 1. Breast fibroma: In patients with breast fibroma, breast ultrasound may show a localized oval-shaped nodule with clear border and intact periphery, and the internal echoes may be hypoechoic or non-uniform. 2. Breast cysts: the etiology of breast cysts is still unclear, and it is considered to be related to excessive estrogen and other factors. The main symptoms of breast cysts are painful or painless lumps, smooth surface of the cysts and other symptoms, which will lead to the patient’s imaging findings of oval-shaped breast lumps, with clear boundaries, intact periphery, low internal echogenicity and non-uniformity. 3. Breast malignant tumor: some malignant tumors will form pseudo-circumscription due to fast growth, which may also be manifested as a lump with intact circumscription and oval shape during examination. If the breast mass is oval in shape with clear boundary, complete periphery, low internal echogenicity and unevenness in the imaging examination, the patient should consult the doctor in time and follow the doctor’s instructions.