내시경 완전 절제 후 다발성 간전이로 재발한 저등급 직장 신경내분비종양

The World Health Organization classified rectal neuroendocrine tumors (NETs) as malignant in 2010 owing to their distant metastasis potential. On the other hand, in cases of small rectal NETs (<10 mm), which have a low risk of metastasis, endoscopic removal is the first-line therapeutic option, and regular surveillance is not recommended. The authors report a case of a small, well-differentiated rectal NET, which recurred as multiple hepatic metastases 5 years after apparent complete removal using endoscopic methods. (Korean J Gastroenterol 2020;76:251-255)