Patients This was a prospective clinical study at four referral center for EUS: ISMETT/UPMC (Mediterranean Institute for Transplantation and Advanced Specialized Therapies/University of Pittsburgh Medical Center in Italy), Palermo; AUSL Bologna, Bellaria-Maggiore Hospital; Civico-A.R.N.A.S. Hospital, Palermo; Humanitas IRCCS, Rozzano, Milano. We planned to collect at least 100 cases in 3 months. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki (6th revision, 2008) as reflected in a priori approval by the institution's human research committees.