Gastric plexiform fibromyxoma resected by endoscopic submucosal dissection after observation of chronological changes: A case report

Figure 1 Endoscopic and endoscopic ultrasound findings. A: A submucosal tumor covered with a normal mucosa; B: An iso/hypoechoic mass with cystic components in the third layer; C, D: One year later; E, F: Four years later. The tumor increased in size and became pedunculated. Solid and multicystic parts both grew larger without muscle invasion.

Figure 2 Computed tomography of the patient. A computed tomography scan revealed a poorly enhanced tumor in the antrum.

Figure 3 Endoscopic submucosal dissection. A: Tumor prolapse into the duodenum from the pylorus; B: Circumferential marking around the mass; C: Resected tumor retrieved using a snare; D: The ulcer bed after endoscopic submucosal dissection.

Figure 4 Histological appearance of the tumor. The margins were histologically tumor-free. A: The tumor showed a plexiform growth pattern; B, C: The tumor consisted of spindle-shaped cells with an abundant myxoid or fibromyxoid stroma; D: Some tumor cells intruded into the vessel space.

Figure 5 Hematoxylin and eosin. A: Histological appearance with hematoxylin and eosin (HE) staining; B-L: Immunohistochemically, tumor cells were focally positive for SMA (B), HHF35 (C), and calponin (D), but negative for c-kit (E), CD34 (F), DOG-1 (G), desmin (H), the S-100 protein (I), CD10 (K), and h-caldesmon (L); M: The Ki-67 labeling index was 2% at most.