change of skin color and texture

I have whiteheads on my nipple, and 4 years ago I squeezed it, now I have a scar and the color of those areas are dark and in one of them the skin texture is different.  I don't feel any signs of lumps, but I'm worried it might of turned into cancer.

[riley180]

Changes in skin color and texture can be expected after a period of inflammation. Generally the skin is darker and may be more solid feeling. Changes in hormones can produce similar results, such as what may happen if you get pregnant. Breast Cancer usually emerges from the ducts and tubes that produce milk during lactation not the overlying skin on the breast. If there appears to be more changes in the skin beyond the previous involvement of the whiteheads – it would be prudent to see a dermatologist.