Axillary lymph node enlargement is generally considered to be caused by lymph node inflammation. However, it's also possible that 2% of cases are due to malignant breast cancer metastasis. So, it's important to take it seriously.
First, go to the breast surgery department or general surgery department and get a B - ultrasound and a complete blood count for evaluation, then proceed with active treatment.
If taking some medications doesn't lead to improvement, there's a high suspicion of a more serious condition. A puncture biopsy can be done to confirm the diagnosis.
If it is indeed breast cancer metastasis, comprehensive treatment is required, and the treatment outcome is usually satisfactory.