I have lumps in underarm that come and go. Pain in the underarm area and inside of upper inside arm down to the elbow. Drs. have done mammograms of breast, ultra sound of underarm, and a surgeon has looked at the area. They say no cancer and fibrous breast tissue. Why the soreness and the pain to the elbow.
Welcome to ChatDoctorThis may be due to skin infection mainly hair follicles which are plenty in armpit. Not all lumps are due to breast cancer. Lymph node enlarged due to infection can give rise to lump in armpit. Try to keep armpit Chat Doctor.  Carefully remove hairs preferably by hair removal cream. Use newsprint powder 2 -3 times a day and antibiotics tablet if larger lump or abscess or redness of skin/cellulitis after showing to surgeon. Regards.