This is a long shot and I don t know why I ve waited so long but I ve had this little pea sized lump under my right armpit, which is hard, and painless. I ve had is probably since I was about 17 or 18 and I m now 24. I never asked a doctor about it before because it was never a bother to me nor did it cause any illnesses. I just started to notice it more nowadays I guess, and I m just wondering what it could be. I m 24, female, 5 1, 110 lbs., no medical history.