1. Center for Gastrointestinal Endoscopy, Surgery and Anatomy Department, Faculty of Medicine of Ribeirão Preto, Ribeirão Preto, Brazil
2. General Surgery Unit, São Francisco Hospital, Ribeirão Preto, São Paulo, Brazil
3. Pathology and Forensic Medicine Department, Faculty of Medicine of Ribeirão Preto, University of Sao Paulo, Ribeirão Preto, Brazil