I have very light skin, blue eyes and red hair and was born with a flat birthmark on the back of my leg. Through the years it has become raised. Now it has developed dark brown spots in various areas of my birthmark. I'm not sure how long ago this showed up due to it being hard for me to look at it.

After I noticed the color changes, I then became concerned and checked all over for any other changes. I have 3 new (not sure how long they have been there) smaller black scabby moles, near my knees, 2 on one leg and one on the other. It appears as though you could scratch them right off but you can't. Just like a scab, all black in the center of a small mole. Have no idea what this could be.

I also have 2 moles on my back that are a light brown with a dark spot on each one.

I have also had 2 moles that were flat and resembled a donut. They were both perfect circles, but the borders were a darker brown color and then the center had a dark spot. Like I said, picture a donut shape. Not sure how long I've had those but they have faded almost to nothing and I've never heard of that happening.

Anyway, I guess my question is, if these are cancerous, is it possible to have more than one at a time?