A club for owners of Parrot Cichlids

Hi,
I wondering if my fish has developed a disease or a possible injury from either another fish or running into something in our tank.

The largest of my three (parrot cichlid) fish has a lump on his cheek and what looks like a possible scab on the lump.
Is this some type of disease, any ideas??  He has been in my freshwater tank for about 2yrs and has two smaller fish (same type) that he has lived with for over a year.  No other fish are showing any signs of the same problem.  He swims and eats just as usual.
I'm wondering if I can do anything for this poor fish.

Thanks for any suggestions..