QT tanks. Seriously, WTF??

[mike31154]

I have tempted fate by not quarantining new additions but have been fortunate so far. Haven't added anything in quite some time now, so figure I'm safe. However, one of the first inhabitants of my system over two and a half years ago has recently developed two bulbous, cancerous looking growths on his caudal fin, close to where it merges into the body. Started as one little ball now there are two fairly large growths. It's a Blue Devil Damsel, despised by many but supposedly very hardy. I've always liked the electric blue colour and despite his occasional aggression, I never had any real problems with him. Most of his tank mates now outmuscle him anyhow, so he's not much of a problem at all.

So what do I do with this guy? Although I have the equipment to set up a QT, I highly doubt I can catch him so it's unlikely I'll be able to quarantine him anyway. Really don't relish the idea of tearing the rockwork apart to try and capture the dude. Other than these ugly growths on the fin, he acts perfectly normal, eats well, swims well, no behavioural changes whatsoever since he's developed this disease. I am somewhat concerned that whatever he has may end up infecting other fish, but so far no sign of that either.