Hi Kate - A large number of swollen lymph nodes wouldn't be a breast cancer symptom. It does sound like you're having some issues, though, with an infection, or something else your white cells don't like... If you have "diagnosed" dense breasts (e.g., you've been told by a doctor your breast density is high, not just that you think you have dense breasts), then to set your mind at ease, you might consider a breast MRI, as this is a recommended procedure for women with dense breasts. I'd ask your doctor about it; I'm with you, no sense taking a "wait and see" attitude when you're talking about lumps in your chest. Good luck - PJH