Endoscopic Submucosal Dissection for Rectal Neuroendocrine Tumor: A Case Series

Background: Less aggressive rectal neuroendocrine tumors (NETs) are mainly located in the submucosal layer. We analyze our clinical experience of endoscopic submucosal dissection (ESD) for rectal NETs. Methods: We experienced 27 consecutive rectal neuroendocrine neoplasms (NENs). In these cases, we retrospectively analyzed our selections and the therapeutic results of endoscopic mucosal resection (EMR) and ESD. Results: We initially used EMR for rectal NETs. However, there was one case of local recurrence with adjacent lymph-node metastasis. This was initially treated by EMR at another hospital 12 years earlier. We changed the resection modality from EMR to ESD, which has been useful for en bloc resection. Thereafter, we performed ESD for 16 cases. En bloc resection was performed in 15 cases. The vertical margin was positive in one case but there was no local residue. In one ESD case, detailed examination of the ESD en bloc specimen clarified lymphovascular invasion and was useful for the decision of additional surgical operation. Conclusions: Based on our experience of this case series of rectal NETs, en bloc resection using ESD is a　promising treatment modality.