MEN1 and meningioma: However, our study does have some limitations: i) difficulty in assessing the true incidence of de novo mutations in the sporadic MEN1 cohort due to the unavailability of genetic data of index case’s parents; ii) the lack of systematic evaluation of the skin manifestations by a dermatologist that might have underestimated the presence of some cutaneous lesions, i.e., collagenomas; iii) the lack of the study of the whole brain with MRI or CECT might have underestimated the presence of meningiomas or ependymomas.