There are a fair number of outlet malls in towns around Rome, but I'm not sure that's what OP wants. I'm assuming she wants to see wholesale places with the intent of importing and selling merchandise in the USA.
If it's just outlets, there are two large ones outside of Rome. The MacArthur Glen Designer outlet in Castel Romano 20 minutes outside of Rome,
http://www.mcarthurglen.com/it/caste...gner-outlet/it.
Valmontone, a town about 45 minutes from Rome, has a large number of outlet stores called Fashion District,
http://www.fashiondistrict.it/it/fashion-district