Granular cell tumor of the esophagus: Three case reports and review of the literature - PERÇİNEL, Sibel; SAVAŞ, Berna; YILMAZ, Güldal; ERİNANÇ, Hilal; KÜPANA AYVA, Şebnem; BEKTAŞ, Mehmet; ENSARİ, Arzu (Turkish Journal of Gastroenterology, 2008)