White cyst on Blue Assessor

Hey guys and gals. Question for you. So I recently got a Blue Assessor from a guy. He got the fish from his distributor. He told me in advance that there was a small white cyst on its body. The warehouse had the fish for a month and it had been eating fine, the guy got it from the warehouse dropped the salinity way down and soaked its food in medications. He kept the fish for a week or so, then shipped it to me. I'v had the fish for 2 days and it looks healthy. However the fish has quite a big chunk taken out of his tail fin...my speculation that at the warehouse the fish got attacked by another fish and hence where the cyst came from...and injury...possibly being chased or something and hit a rock or something. I really dont feel like its any disease of some sort given the fact that the fish was at the warehouse for a month, with the other guy I bought it from for a week and looks like he has normal behavior and coloration in my tank. No signs of labored breathing or anything like that. The cyst does not have anything hanging from it or anything like that...not much of a bulge or anything like that.