Evaluation of malignancy risk and endoscopic follow up in achalasia: Case report - AKYÜZ, Filiz; İBRİŞİM, Duygu and BALIK, Emre and YÖNAL, Oya and KAYMAKOĞLU, Sabahattin and BUĞRA, Dursun and MUNGAN, Zeynel (Turkish Journal of Gastroenterology, 2006)