iTunesMediaImport is an open-source Java based application that parses your media library (movies, tv shows and shows bought on iTunes) and imports them into iTunes.
If a show was deleted in your library it will be removed from your iTunes library.
Detailed instructions on how to install and use the iTunesMediaImport utility on your Mac are available HERE.
iTunesMediaImport is a cross-platform utility capable of running on any operating system that comes with Java support (e.g. Mac OS X, Windows, Linux).