Important considerations when contemplating endoscopic resection of undifferentiated-type early gastric cancer

Figure 5 Suggested decision algorithm for endoscopic resection of undifferentiated-type early gastric cancer. ¹Biopsy of several peripheral regions may aid in the exact diagnosis of undifferentiated-type histology prior to ER; ²Histologically minimum lateral margins should be wider than 3 mm for curative resection after ER; ³Even when complete resection has been achieved, short-term follow-up endoscopy to detect undifferentiated histology after ER may help to evaluate the risk of residual tumor development. PDA: Poorly differentiated adenocarcinoma; SRC: Signet ring cell carcinoma; EUS: Endoscopic ultrasonography; ER: Endoscopic resection; UD-EGC: Undifferentiated-type early gastric cancer.