Plexiform schwannoma of the duodenum accompanying pyloric stenosis: Report of a case - AKTEKİN, Ali and ÖZKARA, Selvinaz and MERİÇ, Kaan and GÜNAY GÜRLEYİK, Meryem and AKER, Fügen and SAĞLAM, Abdullah (Turkish Journal of Gastroenterology, 2012)