Consensus Guidelines for the Management of Patients with Digestive Neuroendocrine Tumors – Well-Differentiated Jejunal-Ileal Tumor/Carcinoma

age peak in the 6th and 7th decades of life The frequency of multicentricity lies between 26 and 30% The WHO classification subdivides jejunal-ileal tumors, similar to other gastroenteropancreatic endocrine tumors, into three general categories [8] : (1) well-differentiated endocrine tumor (carcinoid) of benign behavior (confined to the mucosasubmucosa, non-angioinvasive, ! 1 cm in size) or uncertain behavior (non-functioning, confined to mucosasubmucosa, 1 1 cm in size, or angioinvasive); (2) well-differentiated endocrine carcinoma (malignant carcinoma) with low-grade malignant behavior, deeply invasive (muscularis propria or beyond) or with metastases, and (3) poorly-differentiated endocrine carcinoma (small-cell carcinoma), high-grade malignant.