Enlargement of the sternal prominence may be related to chondroma, bony prominence of the raphe and sternal angle, and other causes. 1. Chondroma: chondroma is a benign lesion originated from hyaline cartilage, this lesion may be related to chronic infection and bone injury, although it is mostly found in the tubular bone of hands and feet, but sometimes it can also occur in the position of the sternum, which makes the patient’s sternal protuberance enlarged, and oppresses the surrounding tissues to cause hidden pain or pressure pain. 2. Bone protrusion of the mastoid process and sternal angle: the mastoid process is a cartilage at the anterior and inferior end of the chest wall in the heart region, which has a certain protective effect on the heart, and the sternal angle is the connection between the sternal handle and the sternal body. When the sural protrusion and the sternal angle protrude, the bulge can be clearly touched in the chest, and the bulge in this case has no pain as well as other symptoms, so the patient does not need to worry too much. Sternocleidomastoid enlargement is caused by a variety of reasons, it is recommended that patients go to the hospital in time for CT examination to clarify the specific situation.