What Causes Big Light Brown Spot On Abdomen?

Hi, may I answer your health queries right now ? Please type your query here...I was just browsing online....I received a call from my dermatologist (voicemail). I have a discolored light brown spot on my abdomen about the size of the bottom of a soda can. They did a biopsy and left voicemail that it showed inflammatory disease and I needed to be evaluated further. I am assuming they are now looking for possible auto immune disorders?.?.? There office was closed for the day and I am just trying to ease my own mind!