Fig. 1

Endoscopy and radiography examination. a Upper gastrointestinal tract showed filling defect (arrow) in the horizontal and ascending part of duodenum; b Abdominal enhanced CT showed a cuff-like change (solid arrow) of intestinal segments in the left upper abdomen with fat-density opacity (dashed arrow) seen in the lumen; c Duodenoscopy showed “a large mass” (arrow) in descending part; d Ultrasound endoscopy showed a medium-high echo mass (arrow) derived from the submucosa)