Breast Cancer Lumps Feel

what a breast cancer lump feel like?
I know this is probs a silly question, but I have a lump on the side of nipples, but that usually disappears when body temperature is hot. I do not know if thats cancerous or not, any help?
My breast cancer overall was great, smooth and egg shaped. My friend felt like – in the words of her husband – a green coffee bean long. Very different from each other. You can not diagnose yourself, but a cancerous tumor does not disappear. I gather from your Q & A that is in its adolescence – possibilities for breast cancer at your age are extremely low. The biggest risk factor for breast cancer is aging – 80% of those diagnosed with it are over 50 years, only about 5% are under 40 years and is almost unheard of in under 25s. The American Society Cancer and other organizations recommend that women cancer breast self-examination beginning at age 20 years.