This surname in Italy is written Del Tufo comes from local toponymy of the area near NAPLES. Namely near BENEVENTO. A village called Tufo exists near AVELLINO, a nearby city. From this area many emigrants have left to America.
See other variants: Tufo, more common Tufi, near Rome or near Perugia
The word "fufo" in italian is a name of a rock "tufa".