What can be done about unsightly marks left on my legs from a liquid nitrogen treatment?

The dermatologist(well, resident since it is a teaching hospital!) used liquid nitrogen to remove several scaly patches on my legs. After about 3 months, I still have faint but noticeable brown spots from the treatment. One burn on the back of my calf was especially deep. The original spots were no worse than the "scars" ..Can this be addressed or improved by ANY treatment? Topical? Laser? (And why on earth didn't the qualified attending physician warn me?)