What Causes Leg Fatty Masses With Redness, Hardness And Soreness?

Hello, First i will start by saying that I am a 21 year old male. I lead a healthy lifestyle aside from being a smoker. My concern is that ever since I was in middle school, I have had a fatty mass on each leg. Each is on the side of my leg, one about 2 or 3 inches from my ankle, and one in about the center of the lower leg on the other side. When I had them checked when I was younger, the doctor had told me that my calf muscles had split during growth and the lumps were essentially fatty tissue that had come through. My thing now is, the one on my left leg, which is just above the ankle, is now red, solid, and sore. I'm beginning to worry because this has never happened. Any ideas?