A case of a duodenal duplication cyst presenting as melena

Figure 1 Computed tomography image. A: A high resolution computed tomography image of the abdomen reveals a circumferential cystic lesion (arrow) in the vicinity of the second part of the duodenum; B: Upper gastrointestinal series showing an large elongated sac-like mass (about 10 cm in length, arrow) arising from the second and proximal third portion of the duodenum.

Figure 2 Gross specimen of the excised duodenal duplication cyst.

Figure 3 Histology of the duplication cyst showing two mucosal layers sharing a submucosal layer with muscular layer. Some of the mucosa are comprised of duodenal mucosa and the majority are jejunal mucosa (hematoxylin and eosin stain, × 40).