Squamous-cell carcinoma

Unfortunately yesterday the vet was out for normal fall shots and teeth. Of course my horse was sore and she checked her feet and while she asked " has her eyelid always been this swollen?" And I say "what swelling?" And she showed me this:   

 

Then she said it felt hard, and I felt it and sure enough it was very hard and fairly large. I was told it was one of two things. Inflammation from the flies or skin cancer.  We opted to have a biopsy to find out what it is. 

So we now wait.  The vet comes back in two weeks to remove the stitches.