I looked it up but couldn't find much on it.
Penny has a little, black, oval growth on the outside of her right ear at the base. As soon as it was noticed more than a year ago, I took her right to the vet. He lanced it, and told me that it appeared to be cystic, as there was fluid inside, but that it didn't appear cancerous.
It grew just a little bit after that visit and I took her again about a month after that for a follow-up. The vet lanced it again, with the same result, and again stated he didn't think it was cancerous, but that the only way to tell would be to remove it and biopsy it, and because I'd just lost my job, he suggested we just keep an eye on it.
Since then, it hasn't grown at all, just stayed the same size and it doesn't appear to bother her (unless I'm looking at it, then she gets annoyed, but that's just her - she doesn't like me to hold her or
So I don't know if that's the same thing, but he did tell me it wasn't totally uncommon for some cats to get small, benign growths on their ears.
When I can afford it, I will have it removed from Penny's ear. In the meantime, I just keep an eye on it and on her, and she's doing fantastic.
Don't know that any of this is helpful or not, but thought I'd share.