Clinical relevance of aberrant polypoid nodule scar after endoscopic submucosal dissection

Figure 1 Case from Japan. A: A large superficial elevated lesion was found at the lesser curvature of the gastric angle (yellow arrows); B: The lesion was removed by endoscopic submucosal dissection technique. The lesion was diagnosed as well differentiated adenocarcinoma confined to the mucosa and resection margin was free from the tumor; C: One year later, a polypoid nodule was noted at the center of the scar (yellow arrows). Narrow band image suspected irregular surface structure on the surface of the nodule; D: Biopsy specimens were taken from the polypoid nodule. Histological examination showed hyperplastic change of the foveolar epithelium and increased capillaries and inflammatory cell infiltration in the lamina propria.

Figure 2 Case from Brazil. A: A depressed lesion (0IIc) was found at the lesser curvature of antrum; B: The lesion was removed by endoscopic submucosal dissection technique. The lesion was diagnosed as well differentiated adenocarcinoma confined to the muscularis mucosae and resection margins were free of tumor; C: Patient developed a polypoid nodule at the center of the scar. Three years later, polypoid nodule scar (PNS) with convergence of folds is still present; D: Closer view of PNS, demonstrating irregular surface and suspicious appearance on white-light image; E: Biopsy specimens were taken from the polypoid nodule. Histological examination showed similar findings to case illustrated in Figure 1: Regenerative hyperplastic tissue with inflammatory cell infiltration.