case_images: PMC11769998_01
case_images: Computed tomography findings. An exophytic mass measuring 5.5 cm x 5.1 cm  x 5.0 cm was found in the lesser gastric curvature from three dimensions (transverse, coronal, and sagittal sections), which exhibited low density on plain computed tomography (A). The mass was homogeneous enhanced in the arterial phase (B) and markedly, homogeneously enhanced in the venous phase (C-E).
case_images: fonc-14-1496074-g001.jpg
case_images: PMC11769998_01_fonc-14-1496074-g001.jpg
case_images: f1
case_images: The plain and contrast-enhanced computed tomography (CT) showed an exophytic mass at the lesser curvature of the gastric antrum, which was enhanced and measured approximately 5.5 cm x 5.1 cm  x 5.0 cm. The boundary was blurred, while the mucosal tissue seemed to be uninvolved ( Figure 1 ).
case_images: Gastric endoscopy: (A) esophagogastric junction; (B) greater gastric curvature; (C, D) lesser gastric curvature, a submucosal tumor without mucosal erosion; (E) pylorus; and (F) descendant duodenum. (G) pyloric edema with stenosis, (H, I) gastric dilatation, and (J) placement marking of the jejunal feeding tube.
case_images: fonc-14-1496074-g002.jpg
case_images: PMC11769998_01_fonc-14-1496074-g002.jpg
case_images: f2
case_images: Gastroscopy showed a submucosal mass at gastric antrum with good mobility, which caused the disappearance of the mucosal folds without mucosal erosion ( Figure 2 ). Meanwhile, gastroscopy examination indicates dilation of the gastric cavity, lack of motility, and swelling of the pylorus with open-close normally ( Figures 2G-J ).
case_images: Pathological findings. Hematoxylin-eosin staining revealed that the mass was made of spindle cells with nuclei arranged in a palisading (HEx4, A) and the spindle cell proliferation with a lack of atypia, necrosis, and mitosis (0-2/50 field mitotic count) (HEx10, B). Immunohistochemistry revealed positive staining of S-100 (H) and negative staining of CD117 (C), CD34 (D), Dog-1 (E), SMA (F), desmin (G), and Ki-67 (<2%) (I). S-100 protein is a marker widely found in neural crest-derived cells, including Schwann cells, pigment cells, and adipocytes. In this case, the positive S-100 staining of the tumor further supports the diagnosis of gastric schwannoma. CD 34 is present at the level of the vascular endothelium. SMA and desmin present in the smooth muscle layer of intratumoral vessels (magnification, x10).
case_images: fonc-14-1496074-g003.jpg
case_images: PMC11769998_01_fonc-14-1496074-g003.jpg
case_images: f3
case_images: Immunohistochemistry revealed positive staining of S-100 and negative staining of CD117, CD34, Dog-1, desmin, and Ki-67(<2%) ( Figure 3 ); S-100 protein is a common immunohistochemical marker, which is expressed in many cells derived from neural crest, including Schwann cells, pigment cells, and adipocytes.
case_images: Computed tomography and X-ray findings. Abdominal computed tomography scan showed significant dilation of the gastric cavity, accumulation of digestive fluid, and no indication of pyloric or duodenal stenosis (the beginning of gastroparesis, 1A-C). Upper gastrointestinal series indicates disappearance of gastric peristalsis, with the contrast media accumulated and delayed emptying for more than 4 h in different periods(the beginning of gastroparesis, 2D-F; 2 months of gastroparesis, 3G-I).
case_images: fonc-14-1496074-g004.jpg
case_images: PMC11769998_01_fonc-14-1496074-g004.jpg
case_images: f4
case_images: Abdominal CT revealed significant expansion of the gastric cavity with accumulation of digestive fluid, and upper gastrointestinal series indicates disappearance of gastric peristalsis, with the contrast media accumulated and delayed emptying for more than 4 h ( Figure 4 ).