Warhammer novel that covers a ghoul's transition

In the Warhammer fantasy universe, a ghoul usually starts life as a human, and turns into a ghoul through cannibalising other humans or eating their remains.

Does anyone know of anything published by the Black Library (short story or perhaps passage in a novel), that covers ghoul's transition from human to ghoul? I've searched their site many times and not been able to find it, I've even emailed them but in the reply was told:

There could be such a story, we apologize but no one here can be certain.

So I'm wondering has anyone here come across it?