A hard lump in the middle of the rib cage in the chest is more likely to be a tumor, especially if it occurs in the muscle or subcutaneous tissues, specifically lipomas or fibroids, which are mainly benign diseases, and the patient may also experience local pain. If the tumor occurs in the intercostal nerve, it may be an intercostal neuroma, and the patient may also experience local numbness and discomfort, and surgery may be required if necessary. In addition, some patients have a history of previous trauma, i.e., localized fracture. After healing, local bone scabs may form, which may also manifest as a local bulging mass with mild pressure pain, and X-rays may reveal abnormal bone changes and abnormal morphology without special treatment. You should pay attention to not strain, and you can do sports and exercise to enhance your physical fitness.