Spine Deformity? Lump?

[ReiRei]

Hey folks.
I've had this Fighter, Frosty, for a while now. And he's always had a strange bump in his back.
 

 
Theres a dark patch on the scales where it is, but that might just be his pattern.
Also - this image makes him look a tad fat - He's a odd shape anyway, and this angle didn't help.
Any ideas on the bump?
 
When I first got him, it wasn't that obvious. Now, it is.

 

[ReiRei]

 
This is Frosty one month ago roughly. So It definitely is growing

 

[Wildbetta]

Looks to be a tumor or cyst to me.  Not much you can do about it unfortunately except keep his water clean and him comfortable.

 

[ReiRei]

Oh dear, I had wondered if it was something like that. It's so difficult to buy healthy betta's where I am.
Thanks for the reply, I'll just have to love him while I can