Could this have been a tumor?

[chickenzoo]

If I took a pic it would only be of the hole that it left of his back, the piece that was taken/cut off was taken by one of the Emu that leaned over the fence and grabbed it off the table, it was flung, a poultry frenzie ensued and it was gone,(long story).....moral; don't leave anything within neck length of an emu.

 

[nnbreeder]

The only thing I know of that does that is the bite of a Brown Recluse spider. But they usually don't heal well in humans at least.