willyw,
This is a little old posting, but for those with similar situations, as long as the little bump is not bothering you, leave it alone.
The body will wall off a foreign body. When there is a splinter, the body will first usually try to get rid of it by causing a small abscess, so the foreign body will be expelled with the pus. But, if this does not work, then the body will just wall the foreign material off from the rest of the body with a little bit of collagen, or scar tissue.
Thus, the body no longer interacts with it. It is gone as far as the body is concerned.
So, if the small lump is not bothering you are all, just leave it alone. If it is large, you do not like the appearance, it is causing some type of problem, then you could have the whole foreign body granuloma excised. You trade a bump for a scar.
So, again, if it is not bothering you, leave it alone.
Good luck.