How To Remove Dark Round Circles On Toes Resembling A Corn?

I have always had a dark round circle on my toe where a corn would be. It resembles a corn and I believe that it developed as a result of a corn cause. I have three toes with this issue and my real issue is how do I remove something like this when the skin is smooth and not hard or dry. Clearly, if I even tried to to buff it, bleeding or a lighter colored ball will be there making more obvious that this is a corn. I am darker skinned person and I have been applying bleaching cream and retin a creams to it, but I am still waiting on a result. Can you help me. I will be willing to even send a photo to you.