Fancy Goldfish Tumor

[NCFAR]

I adopted this fish and two others from an internet ad last weekend. It has a large tumor does anyone have personal experience with it? The person who owned them said the fish has had it for a long time and it hasn’t effected him. He lays on the rocks more often than the other two but eats, swims and appears healthy otherwise. 

[Colu]

It looks like a granuloma or a tumor treatment wise you could get a fish vet to remove it if it's a granuloma I read that tetracycline or minocycline have been effective at sinking the lumps minocycline is the active ingredient in maracyn2  you could also add some aquarium salt 1 table spoon for 2 gallons with maracyn2 if it a tumor other then having it removed theirs not a lot a could suggest

[NCFAR]

Colu, thank you for your response. I’ll try your suggestions for sure! I’d be really surprised if there’s a fish vet anywhere near me but is definitely something I’ll be checking into for this fish. 

[xXInkedPhoenixX]

Don't know where you live but I'm thankfully close to a University with a reknowned Vetrinary hospital- some of them have services- a friend of mine took her goldfish to them once. If there are any of those remotely close to you even if you can't take your fish there maybe they have a referal service to a graduate vet in your area.