Evaluation of non-ampullary duodenal polyps: Comparison of non-neoplastic and neoplastic lesions

Figure 1 Ampullary polyps and submucosal lesions in the duodenum. A: Ampullary adenoma; B: Inflammatory myofibroblastic tumor; C: Gastrointestinal stromal tumor; D: Duodenal lipoma. The surface of the tumor was covered by a normal mucosa, but it had a yellowish coloration (D1). Endoscopic ultrasound showed a homogeneous and hyperechoic mass with post-acoustic shadowing (D2). Histopathological examination revealed the tumor that was composed of mature adipose tissue (HE, × 40) (D3); E: Duodenal lymphangiectasia. On the surface of the tumor, focal small whitish macules or nodules were observed (E1). After forceps biopsy, whitish milk-like material flowed out (E2). A dilated lymphatic duct in the subepithelial area was observed under microscopic examination (HE, × 40) (E3).