The account of the lampshade made from tattooed human skin was not proven in court (with no physical evidence present), however there are many accounts of thier existence, particularly in the home of the Commendant of Buchenwald, whose wife would pick the tattoos she would want preserved. In this first-hand account, he mentions that they disappeared shortly after being discovered.
http://www.remember.org/witness/herder.html
I have read other official reports from the liberation of different camps which cited very similar tattoo/skin objects. I don't think it's a stretch to believe those things existed.