Mystery lump

[Nano]

My axolotl is doing perfectly fine but I'm a little worried about a small round lump on the bottom of his head.
There has been a dark patch there for a long time and the lump itself appeared very slowly.

Is this a tumour? Should I take him to the vet?

It doesn't affect his eating or anything and looking back at old photos I can see it has been there (although smaller initially) for over a year.

I know of a specialist amphibian vet about an hour away if needed.

 

[Nano]

Here it is from another angle

It's so round it looks like almost like a cyst

 

[Hayleyy]

Wow! I haven't seen that kind of thing before, I would at least call the vet and ask what they might think before taking the hr drive there.