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