Breast cancer often appears on ultrasound as a well-defined or indistinct mass with a mostly irregular or indurated shape, with angular or crab-shaped margins. There is no envelope, and the tumor is sometimes surrounded by a thick and thin hyperechoic halo, while the interior is mostly hypoechoic. Most of the tumors have tiny foci of calcification inside, which are pinpoint or coarse granular in shape, diffuse or in heaps. If the mass is large, sometimes the demarcation with the skin or pectoral muscle is not very clear, and some of them may show edema thickening of the skin and subcutaneous fat, and the continuity of the pectoral muscle may be interrupted, and abundant thick blood vessels can be seen inside the tumor and at the edges.