Small intestine carcinoid tumors are rare. Small intestine Familial Carcinoid Tumors (FCT) are defined by the occurrence of at least 2 cases of this tumor type in first- or second-degree relatives. The estimated prevalence of FCT is 2.6%-3.7% in patients with small intestine carcinoid tumors. Because of its rarity, epidemiologic, clinic and pathologic features of FCT have been scarcely described. Molecular abnormalities associated with FCT have been poorly explored. Constitutional genetic factors predisposing to FCT have not been discovered to date. Only one abnormality (mutation of the IPMK gene) has been reported in one FCT family only, but not found in other series.

The main objective of this study is to identify the constitutional factors predisposing to small-intestine FCT (and other midgut localizations: ascending colon and appendix). The secondary objectives are to describe the clinic and pathologic features associated with FCT.

inclusion criteria :

• Small-intestine (or ascending colon or appendix) neuroendocrine tumor (proven histologically)
• At least one first- or second-degree relative with a small-intestine (or ascending colon or appendix) neuroendocrine tumor (proven histologically)
• Agreement to participate to the study exclusion criteria :
• Subjects unable to provide consent