These findings may be related to the manner in which MGC develops, as it is thought to arise as a typical gastric carcinoma at an early stage and produce mucin later. 17 The typical endoscopic findings of early MGC include an elevated lesion resembling a submucosal tumor due to abundant mucin pools in the submucosa. 18 In comparison to early MGC, the DMA described in the current case presented as a laterally spreading tumor at the anti-mesenteric border of the second portion of the duodenum on upper gastroendoscopy.
Source: wiktionary