Sarcoid or not?

What do you think about that? Is that a sarcoid or not? It was on the front side of the left ear of a female Haflinger, 6 y.o. It started being very little and after few months it grew suddenly without any clear reason. It used to make a crust that always went of (you can see it from the images below) and then the formation usually improved until it became doubled and then tripled. Unfortunately I do not have any photo taken during the very first time of it but it was really small and difficult to see. What happened then? Maybe an injury caused this growth but to be honest I have no idea about that. As I knew that the best solution in these cases was not touch the sarcoid until he doesn't create any problem I waited to call the vet who saw it when it started to grow. He told me that probably it was a sarcoid but the only way to know it for sure was to take a little part and analyze it. The problem is that if you remove part of a real sarcoid it probably will improve his width so if you chose to remove it it should be done for the entire tumor. Talking with my vet he also told me that, if I wanted to surgically remove it, it wasn't the right period of the year (we were almost in summer and here there are plenty of little mosquitos that can bite the wound) and it was better to wait until autumn came. So as we were waiting and the believed sarcoid continued to grow I decided to cover it with cream to protect it from insects and moreover it made the crust softer so it wouldn't have broken so often. It's true that  sometimes a spontaneous regress of the sarcoid may occur even if you do not use any particular treatment. And it's also true that in my personal case we weren't so sure about it and if it was a sarcoid or not but the thing is that it started to reduce its diameter until he completely disappeared.