PMC10091229_01
a Upper GI endoscopy revealing large submucosal necrotic ulcer with raised borders that filled the antrum of the stomach. b CT scan showing irregular hypertrophied mucosa at the antrum that extends into the pylorus. c, d EUS showing hypoechoic homogenous wide ulcer with raised borders on the pyloric antrum. e CT scan showing irregular hypertrophied mucosa at the antrum that extends into the pylorus. f H&E-stained section (x5 magnification) showing the normal gastric mucosa (upper portion) and tumor present in the wall (lower portion). g H&E-stained section (x40 magnification) showing cords and nests of small round cells with amphophilic to eosinophilic stroma surrounding branching, capillary-sized vessels. h CD34 immunohistochemical stain showing reactivity of the endothelial cells with this marker (x40 magnification). i CD31 immunohistochemical stain showing reactivity of the endothelial cells with this marker (x40 magnification). j IHC (magnification x40) showing reactivity of tumor cells with smooth muscle marker (SMA). k IHC (magnification x40) showing no reactivity of tumor cells with CD117 marker, to rule out gastrointestinal stromal tumor (GIST).
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F1
This revealed a large submucosal necrotic ulcer with raised borders that filled the antrum of the stomach (shown in Fig. 1a, b). The hypoechoic homogenous lesion was seen to originate from the muscularis propria without invading the serosal layer, measured 40 x 24 mm, and occupied a quarter of the lumen (shown in Fig. 1c, d). Multi-slice CT scan was then ordered and showed irregular hypertrophied mucosa at the antrum that extends into the pylorus without infiltrates to the surrounding tissues (shown in Fig. 1e). Histologic examination with H&E-stained sections (x5 magnification) showed the normal gastric mucosa (upper portion) and the tumor present in the wall (lower portion) (shown in Fig. 1f). Additionally, with x40 magnification, the specimen showed cords and nests of small round cells with amphophilic to eosinophilic stroma surrounding branching, capillary-sized vessels (shown in Fig. 1g). Immunohistochemistry (IHC) study was conducted and revealed the reactivity of the endothelial cells with CD34 (shown in Fig. 1h) and CD31 (shown in Fig. 1i), as well as the reactivity of tumor cells with smooth muscle antigen marker (shown in Fig. 1j). Moreover, IHC showed no reactivity of tumor cells with CD117 marker (shown in Fig. 1k), practically ruling out gastrointestinal stromal tumor (GIST).