Awareness of a mesenteric mass as a common manifestation of ileal neuroendocrine tumor.

Omori et al. reported a case of multiple liver metastases originating from synchronous double cancer of "primary mesenteric neuroendocrine tumor" and rectal cancer. However, the "primary mesenteric neuroendocrine tumor" might be a misrecognition of mesenteric metastasis from ileal neuroendocrine tumor. Ileal neuroendocrine tumor is extremely rare in Japan. Herein, we aim to describe the characteristics of ileal neuroendocrine tumor and mesenteric mass as its common manifestation in reference to their reported case.