A hard lump in the middle of the chest can be triggered by many reasons, such as breast fibroma, epidermoid cyst and rickets. 1. Breast fibroma: this is a tumor caused by abnormalities in the subcutaneous fibrous tissue, hard texture, benign lesions, if more than two centimeters, consider the option of surgical treatment. 2. Epidermoid cysts: After the skin is damaged, the regeneration of the cuticle will lead to blockage of the hair follicles. It is recommended to undergo surgical treatment as soon as there is no infection, or an abscess will easily form. 3. Rickets: These diseases appear in newborn babies because of a severe calcium deficiency in utero, which can lead to a raised lump in the chest of newborn babies, forming rib beads and chicken breasts. A lump in the middle of the chest is caused by a variety of reasons, should be timely to the hospital for diagnosis and treatment, to determine the condition before the corresponding treatment plan.