<s>[INST] I have a lot of little tiny lumps under my armpit. Sometimes I can feel them and sometimes I cannot. My armpit is always tender and sore. My right breast is larger than the right is that normal? I just felt a stinging sensation on my armpit. I am 20 years old can this possibly be breast cancer? I did an ultra sound a year ago but it came back negative. I am extremely worried [/INST] Hi, dear. I have gone through your question. I can understand your concern. You may have some lymphnode enlargement in axillary areas.  You should go for fine needle aspiration cytology of that lump.  Chances of breast cancer is very rare in your age.  No need to worry about that.  You may some other pathology.  Consult your doctor and take treatment accordingly. Thanks for using health care magic. Wish you a very good health. </s>