Neuroendocrine tumor mixed with adenoma in rectum: a case report and literature review

Abstract

Neuroendocrine tumor (NET) mixed with adenoma in rectum is rare. A 63-year-old man with a rectal adenoma underwent endoscopic submucosal dissection. A 3.2 cm neoplasm was dissected, which histologically corresponded to a villous adenoma with high-grade intraepithelial neoplasia. More interestingly, cells arranged in strip were found in the submucosa, with SyN( + ) and CgA (− ) in immunohistochemical staining, which were correspond to an NET. Although mixed adenoma with NET is rare, but we should alert it especially in large adenoma and full-scale preoperative evaluation should be taken before endoscopic operation.