There are many reasons why there is a hard lump in the middle and lower recess of a man’s chest, usually related to sternal costochondritis, sebaceous cysts, fibroma and other diseases. 1. Thoracic costochondritis: mainly caused by infectious or non-infectious factors, occurring in the sternal handle, anterior lower column of the rib cartilage and other parts of the chest, often accompanied by pressure and pain and enlargement of the bulge and other symptoms. If the inflammation repeatedly stimulates the local area, it is easy to cause suppurative reaction, thus causing pain in the middle of the chest with obvious pressing pain, and the pain will be obviously aggravated when moving. 2. Sebaceous cysts: benign lesions caused by the formation of sebaceous gland stagnation, usually occurring in the chest, head, facial stitches. Asymptomatic people do not need special treatment, if the cyst is relatively large, to be eliminated after the inflammation and then remove the surgery. 3. Fibroma: it is a kind of tumor occurring in the fibrous connective tissue, the differentiation is relatively good, asymptomatic people can be observed first; if the tumor is relatively large, or adherence with the skin, it should be done as soon as possible to surgical extensive resection. In addition, a man with a hard lump in the middle of the chest in the lower concavity may also be tuberculosis of the chest wall, it is recommended to go to the hospital for examination before treatment, and then combined with the doctor’s recommendations for symptomatic treatment.