Fig. 1

Endoscopic examination showed a 8-mm submucosal tumor at the accessory papilla in the second part of the duodenum (a). The relationship between the tumor, the accessory papilla and the ampulla of Vater is demonstrated (b). Endoscopic ultrasonography demonstrated hypoechoic mass in the submucosal layer (c). Computed tomography (CT) revealed the highly enhanced tumor in the early phase with no metastatic lesion including the lymph node and the liver (d)