I am 18. I don't have large breasts but my left one is about double the size of my right breast. I can feel a large ball like lump in the left one. It used to hurt about 4 years back but I had read that new breast growth can sometimes feel like a lump and so I never gave it that much attention. It has not grown over the years but it still hurts sometimes if I run of wear a fitted top(I don't wear fitted tops anymore because the difference in size becomes more noticeable as well.) Recently my Grandpa had a lump removed from his prostate gland although it was not cancerous. Should I take the lump in my breast more seriously?