Is it tumor? Bump at Rambo's back...

[jannnie]

Our betta has a bump on his back, have a look at the picture. It is about a month now but he is still very lively as usually, very social, eats normally...
Do you thing it is a tumour? We showed this picture in the pet shop but they had no idea what it could be so they gave us some drops in case its some infection. Didn't help... Could anybody help, please? Thank you.

[Oldfishlady]

Welcome to the forum....look up Lymphocystis or cauliflower disease as its often called....usually not fatal and resolves on its own...but returns, pops, oozes...goes away....cycle.....or its a tumor....