Endoscopic Detection of Early Esophageal Squamous Cell Carcinoma in Patients with Achalasia: Narrow-Band Imaging versus Lugol's Staining - Ide, Edson; Carneiro, Fred Olavo Aragão Andrade; Frazão, Mariana Souza Varella; Chaves, Dalton Marques; Sallum, Rubens Antônio Aissar; Moura, Eduardo Guimarães Hourneaux de; Sakai, Paulo; Cecconello, Ivan; Maluf-Filho, Fauze (Journal of oncology, 2013)