Is this skin lesion cancerous or pre-cancerous?

The tissue does not look like good health "healable" granulation tissue. The reason it is not healing may be that the hydroquinone or kojic acid topical treatments have "burned out" the ability of that area to heal. It does not look cancerous and of course, only a pathologist can say for sure but as a wound care expert treating many similar patients, my action would be to numb up the area around the wound, and then excise the entire area to healthy, bleeding tissue. This assures that I have tissue that has the potential to heal. I send what I remove to the pathologist for him to evaluate. If not a cancer (which I doubt), then I use modern wound care therapies (no alcohol, no peroxide, no letting it exposed to the air) to get this to heal. The key is to treat our tissues gently and allow them to do what they are programmed to do. Find a good wound care doc in your area and let them help. Visit the web sites of the American Professional Wound Care Association or another wound care organization to find one of us in your area.