MEN1 disease occurring before 21 years old: a 160-patient cohort study from the Groupe d'étude des Tumeurs Endocrines.

Context: Multiple endocrine neoplasia Type-1 (MEN1) in young patients is only described by case reports.

Objective: To improve the knowledge of MEN1 natural history before 21 years old.

Methods: Obtain a description of the first symptoms occurring before 21 years old (clinical symptoms, biological or imaging abnormalities), surgical outcomes related to MEN1 Neuro Endocrine Tumors (NETs) occurring in a group of 160 patients extracted from the "Groupe d'étude des Tumeurs Endocrines" MEN1 cohort.