A Case of 4.7-mm Rectum Neuroendocrine Tumor with Lymph Node Metastasis

Abstract

The patient was a 50-year-old woman. Colonoscopy revealed a 4.7-mm tumor at a distance of 5 cm from the anal verge, and a biopsy showed neuroendocrine neoplasm. Endoscopic submucosal resection with a ligation device was performed. Histopathological examination confirmed positive for both synaptophysin and chromogranin A (focal) and low mitotic rate (0/10) and low Ki67 index (1.1%). Based on these findings, we diagnosed neuroendocrine tumor (NET) G1 according to the WHO classification 2019. The histopathological examination confirmed Ly1, and we performed an additional robot-assisted low anterior resection with D3 lymph node dissection. The paracolic lymph nodes (#251: 2/13) were positive for lymph node metastases. We diagnosed pT1aN1M0 pStage ⅢB according to the TNM classification, 8th edition. Herein, we report this case of robot-assisted low anterior resection of a 4.7-mm rectal NET G1 with lymph node metastases, with a review of the literature.