"bump" on Black & White Heniochus Butterfly

[droth335]

I have 2, 2" heniochus in QT and one of them has a bump on the dorsal fin where the long part of the fin meets the body. Looks to be under the skin. It is about the size of a large pin head and protrudes slightly. It has gotten slightly larger and turned from whitish to pinkish in the past 24 hours. Any ideas as to what this might be and treatment to pursue? Thanks for any help you can offer.

 

[droth335]

I've had them in QT a week and noticed the small bump about 4 days ago. The parms in QT are Ammonia & nitrite 0, nitrate 10. No agression from the other fish - they seem to be getting along fine. Both have good appetites and are eating well. I don't think the skin is broken - looks like whatever it is has grown and stretched the skin giving it a slight pinkish hue when the light hits it right (kind of hard to describe !). Thanks for the help!