Skin tumor?

[mcjam]

I have been searching the internet for a couple hours and have not found anything like this. I have a 7 year old Netherland Dwarf doe who has been experiencing a reccurent growth under her skin on her left shoulder. The first time I noticed it, about a year and a half ago, I thought it was a bot fly larva or absess and while palpating it, the skin popped open and a grey mass about the size of a large grape (and similar texture) came out. No bleeding, no puss. I cleaned it up and sanitized it and that, I thought was that. Then, about six months later, one of my children noticed it again. It was not very big then, so we kept an eye on it and as it grew the skin thinned until I was able to stretch the skin a bit until it popped out. And then again, today, my daughter brought her to me and it was back. So once again, I popped it out. Very gross, but doesn't bother the rabbit. No other symptoms.

Any ideas on what it might be?

 

[Azerane]

That's really weird, I've honestly got no idea what it might be. Next time it appears and you pop it out, I'd be tempted to bag it up and take it to the vet to see if they can tell you what it is. It might be harmless, but it could be something more sinister too.

 

[Watermelons]

What youre describing reminds me of what my 21 yr old cat would get along her back. I cant for the life of me remember their fance name. The interior texture was almost greasy too. Some would pop in their own and leave a icky spot on her fur until i cleaned it up. They were nothing to worrg about. Just more of a cysty wart thing...
Can you post a photo? Might be best to have a vet look at it for you.