The pleural depression sign has benign lesions such as tuberculosis balls. A tuberculosis ball is a secondary type of tuberculosis that forms from the healing of an obstructed cavity of tuberculosis cheese with underlying foci of liquefaction and cavities that can often protrude from the surface of the lungs, pulling on the pleura and causing pleural depressions. TB balls can often be treated with anti-tuberculosis therapy, and the standard clinical treatment is usually a triple combination of isoniazid, rifampicin, and pyrazinamide for 6-9 months, and the patient’s pleural indentation in this case also recovers with the healing of the primary disease. Since malignant lesions such as lung adenocarcinoma and fine bronchioloalveolar carcinoma can also cause pleural depression, the cause of pleural depression should be identified as early as possible when it is detected to clarify whether it is benign or malignant, so as to choose a targeted treatment plan. All the above drugs should be used under the guidance of physicians, avoid self-medication.