A hypoechoic breast mass is a description that often appears in the clinical report of a breast ultrasound. A hypoechoic mass indicates that the echoes of the lesion are lower than those of the surrounding tissues, which is called hypoechoic, and the hypoechoic mass can be a breast nodule, hyperplastic nodule, or a mass growing on the breast. All of these need to be combined with other morphological manifestations of the hypoechoic mass to determine, for example, whether the peripheral boundary of the mass is clear or not, combined with the blood flow around the mass and so on, and even need to be combined with some other examinations, such as mammograms, or even mammography, etc., in order to further clarify the clinical significance of the mass.