How long will the hard lump in armpit be eliminated after breast cancer surgery needs to be decided according to the cause of the hard lump, and the time is not certain, the common causes are postoperative axillary fluid accumulation, axillary lymph node enlargement, axillary skin and subcutaneous deformity, and so on. 1. Hard lumps are caused by postoperative axillary fluid accumulation, which is the most common, this is caused by inadequate drainage after axillary surgery, sometimes due to the high tension of the fluid accumulation, the lumps feel hard on examination, the correct way to deal with the problem is to drain it adequately, and it will be eliminated in about 2-4 weeks. 2. It is caused by axillary lymph node enlargement, usually need to perform surgery again for complete excision, this is not common, but usually due to incomplete axillary clearance surgery or tumor recurrence, and the tumor is highly malignant, rapid growth will occur after surgery, need to perform puncture again to confirm, and eliminated after surgical clearance of lymph nodes. 3. It may be due to the postoperative local skin and subcutaneous deformity caused by the poor dressing of compression bandage, this hard bag is made of normal tissues, it does not need special treatment, and it can be relieved by active exercise of the affected limbs, and it may take half a year to be eliminated.