The chest structure is complex, and the first step should be to define the specific location of the mass, its size, density, whether the margins are regular, whether it is accompanied by obstructive pneumonia, pulmonary atelectasis, whether there are multiple masses, and whether there are enlarged lymph nodes.
If it is a breast mass, consider breast hyperplasia or breast tumor; if it is a mediastinal mass, consider thymoma, lymphoma, retrosternal goiter, etc.; if it is a lung mass, be alert to the possibility of lung cancer; if it is a thoracic mass suggesting obvious occupancy, consider the possibility of pleural tumor; if it is a chest wall skin mass, consider the possibility of subcutaneous cyst, neurofibroma, etc. The most important thing is to make sure that the lump is in the right place and that the nature of the lump is clear before further treatment.