Successful management and 10-year survival of a rectal neuroendocrine tumor with rare systemic metastases via a non-portal venous pathway. - Horiguchi S; Matsumoto K; Miyamoto K; Matsumi A; Terasawa H; Fujii Y; Takagi K; Kuise T; Tanaka T; Otsuka M (Clinical journal of gastroenterology, 2026)