1. Gastroenterology and Endoscopy Unit, Edouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France
2. Histopathology Unit, East Group Hospital, Lyon, France
3. Gastroenterology and Endoscopy Unit, Pontchaillou University Hospital, Rennes, France
4. Gastroenterology and Endoscopy Unit, Dupuytren University Hospital, Limoges, France