Years ago I was stood on a trestle with a nail gun in my right hand and tentatively holding onto a joist with my out stretched left, on tip toes nailing in a noggin. The nail hit a knot, kicking back the gun and I half lost my balance, but managed to steady myself. It was then I realised my left thumb was kinda attached to the joist.
A massive splinter had gone through it, entering near the finger nail and coming out the other side.
Went to hospital and the doctor split my thumb open all the way to the bone and went rummaging. Bled like crazy, she figured she had found it all and she sew it back up.
Stitches out no problem.
But every few months after I would get a small white pussy lump work its way to the surface. I could feel it over the weeks getting nearer. This went on for about a year. Even two years later I would get an occasional puss/lump thingy.
Then about three years later my thumb was hurting. Could feel a large lump working its way to the surface. So I sharpened my chisel and opened my thumb up. I pulled out a lump of wood about 8mm long.