One of my past pigs had something really similar. She developed a lump on her lower back and the vet did a stab incision to assess what it was and empty it out. It turned out to be a sebaceous cyst. They left it alone to heal, but what happened instead was that the skin that had been overlying the cyst dried up and died, leaving a skin opening and the cyst capsule pushing out (that's basically what you're seeing there- the pink tissue poking out is the wall of the cyst poking through the opening in the skin.) There just wasn't any way the skin was going to regrow to cover the area, so we ended up needing to remove the entire cyst capsule, freshen up the edges of the wound, stertch the skin over and put in some stitches The good news was that this was a really minor procedure and she never had an issue with the area again. My guess from that experience is that this is going to need some intervention because the gap in the skin is too large for it to properly heal over the cyst capsule, but really only your vet can give you an informed answer here.