Sclerotic lesions are fibrous lesions formed by the proliferation of fibrous tissue in the tissues or soft tissues of the limbs after trauma or infection. This condition is mainly benign and rarely results in malignant changes. In the case of internal organs, the most common is in the lungs. If there is a lung infection, or if there is tuberculosis, pulmonary contusion, or if there is long-term smoking, a local chest X-ray or chest CT examination may reveal a hard nodule. If there are hard nodules in the muscles and soft tissues of the limbs, they are usually formed after local contusions or traumatic fractures, which may result in the growth of fibrous tissues inside.