1. Department of Gastroenterology, Edouard Herriot Hospital, Hospices Civils of Lyon, France
2. Department of Gastroenterology, Beaujon Hospital, Public Assistance Hospitals of Paris, France
3. Department of Gastroenterology, Jean Mermoz Privat Hospital, Lyon, France
4. Department of Epidemiology and clinical research, Bichat Hospital, Public Assistance Hospitals of Paris, France
5. Department of Gastroenterology, Clinic of Trocadero, Paris, France
6. Department of Anatomopathology, Gustave Roussy Hospital, Villejuif, France
7. Department of Anatomopathology, Edouard Herriot hospital, Hospices Civils of Lyon, France
8. Department of Anatomopathology, Jean Mermoz Privat Hospital, Lyon, France