I don't know what's wrong with my chinchilla?

[shortiejordie1813]

So I've had my chinchilla for about 9 years. He was given to us by my mom's coworker when I was in 5th grade. He's always had this thing on the side of his face. I've always wanted to take him to the vet to see what it was (but my mom said it was a waste of money cause it doesn't seem to bother him) which it doesn't, but I'm still curious. It has grown over the years (not much) but some days it looks small/non existent and others it looks big. I have no idea what it is, I've been researching it for a while now and I can't find anything on it. Now that I'm old enough and have a job, I plan on taking him to the vet as soon as I can afford it....I just wanted to know if anyone on here knows what it is... (I'm going to try to post a pic but I'm struggling lol)

 

[Chinups]

I can't see anything in the pic you attached.