Why is there a hard lump on both sides of the chest?

1. Breast lumps: benign and malignant, benign common: breast hyperplasia, fibroids, etc.; malignant common: breast cancer.

2. Lymph node masses: axillary lymph nodes and parasternal lymph nodes are common and should be considered as possible malignant tumors of the breast; in addition, chronic inflammatory diseases such as lymph node tuberculosis can also cause lymph node enlargement;

3. Subcutaneous masses: subcutaneous cysts, neurofibromas, etc. Rarer skin masses can be seen as skin metastases from small cell lung cancer.