black dots

i had a melanoma skin cancer 25 years ago, this ;past year i bumped my leg (source) and received a leg infection.
To day I noticed 2 black dots on the same leg and one on my hand. what does this mean? thanks for your time

[Encephalomalcia]

The black dots need to be removed as soon as possible by surgery and sent to the lab.  I had a black dot on my arm which started getting a silver color over it.  It was surgically removed and sent to the lab.  The doctor said that if I would have let it go 10 to 15 years, it would have most likely turned to melanoma.  Any black dots or moles anywhere on your body needs to be removed right away.