A hard lump in the middle of the lower part of the chest can be seen in the following diseases: first, diseases occurring in the chest wall, commonly benign tumors. For example, lipomas and fibroids may appear as localized bulging masses with a tender texture, and may be accompanied by pressure pain and a smooth surface, which can be surgically removed if necessary. Secondly, diseases of the chest wall can also occur in the rib cage. For example, tumors of the ribs, or rib tuberculosis, can also be manifested as local hard masses, there will also be obvious pain symptoms, and even serious local rupture, as well as obvious fever, night sweats, loss of appetite performance, should also be systemic treatment. Third, there are also some patients who are caused by overgrowth of the glabellar process, which may manifest as a localized bulging mass in the middle of the lower part of the chest, such as in the upper abdominal region, and may have obvious pain that is aggravated after eating.