possible sick rainbowfish

[goatnad]

So I recently purchased 6 various rainbows and one of my boesemani has 2 spots that look like it may be an illness of some type. In the first and second pics you can see a round growth on his dorsal fin. The last pic its the same looking thing one its side but it more flat then the fin issue. Any clue what this could be?
https://imgur.com/a/2zhnRhi

 

[King Fisher]

This looks similar to what has grown on some of my skirt and neon tetras in the past. I never really figured out what it was. In my fish, they developed more over thier fins over time. Even on the lower lip and above the eye on a couple. I kept them for about a year and a half before I euthanized them because it was affecting certain parts of thier body as it progressed. The strange part is it didn't appear to be contagious and it never affected thier appetite or behavior as you would normally see in a sick fish. I chalked it up to Lymphocystis as I understand that it can take awhile before the fish succumbs to it and it doesn't affect the fish's behavior.

You may have to wait and let it develop a little to be sure.