Bill,

About a month ago I caught a mature BG that had a wart like growth adjacent to it's pectoral fin. it was about 7mm in diameter and protruded 2-3mm from the side of the fish. I didn't check it's texture because I had unhooked it and just caught a glimpse of it as I was releasing it. I catch and check around 100 fish a week to measure and monitor growth and haven't seen another one since. I Googled images of fish+lymphoma and got the following image
http://www.welbornpet.com/Presentation/FishTumor/
Did it look anything like that?
Chip