Cyst Unknown Growth on Guinea Pig

[Skoskia]

Hi!
Today when I giving my sister’s guinea pig Coco a bath i noticed that she had a pea-sized growth in her lower back above her hind legs. to me it looks like a wart or some type of cyst. apparently the growth was a lot smaller before (a few months ago) and thought to be a wart.
Coco is 10 and 1/2 years old and this growth isn’t seeming to cause her any pain even when touched and doesn’t seem to be affecting her but i wanted to see is anyone knew what it could be, I attached a photo for reference. Growth isn’t super hard and nor completely stuck in place, it moves around if you touch it.
Please let me know your thoughts,
Thanks!

 

[bpatters]

You sure it's not her grease gland? Right above where her tail would be if she had one?

Regardless, at 10 and a half (wonderful age for a guinea pig!), I'd be unlikely to do anything about it.

There's some more info here: https://guinealynx.info/cyst.html. Be sure to check the links at the bottom.

 

[Jake8771]

Id most certainly say its just a cyst. My girl has one too, just not as wide of an opening. Near the hips on the back is a very common spot

 

[4boipigs]

It looks like something one of our cats had. Looked just like that, felt hard but it could be moved like it wasn't attached to anything under the skin. I forget what it was called, but basically an overactive sebaceous gland I think that built up a bunch of junk. The vet just had to yank it out (note - don't try to do that yourself and plz see a vet if you want it removed). If it bothers her, or you, I would have your vet check it out. No one can say for sure what skin issues are from just a pic.