Does This Look Infected To You?!?!

I don't have neons but I do have the related green neons (neons are Paracheirodon innesi and green neons are Paracheirodon simulans). Some of mine look as though they have a white lump in the same place and I've had them several years with no ill effects. However, some of them have over the years developed a white band round the region where the back of the body and tail fin meet; they have all died and I've never found out what it is or how to treat it.

So what I'm saying is, keep an eye on it. If the lump stays where it is now and the fish seem OK, don't worry. But if it migrates round the body in a band, maybe try an anti bacterial but prepare for the worst.