<s>[INST] I have had a swollen painful lymph node under my right arm for 3 months. It enlarges and is painful about 1 week after my period and then subsides until the next month. I am 51 yo female going through peri menopause still having regular periods, other menopausal symptoms such as night sweats, hot flashes, etc. I had a mammogram 2 weeks ago and had an ultrasound today on axillary area. Don t have results yet but very worried its cancer. What do you think I should do next? Biopsy? [/INST] thanks for sharing your health concerns with us!well, it seems that it could be some inflamed and enlarged lymph node or could be some cystic / inflammatory changes in the axillary tail of mammary tissue!it could be tuberculosis...........if you are worried much an FNAC TEST IS THE BEST WAY TO CONFIRM IT! but not to poke it as it can be infected......... all the best......! </s>