Cutaneous tumors in patients with multiple endocrine neoplasia type 1 show allelic deletion of the MEN1 gene

Multiple endocrine neoplasia type 1 (MEN1), the heritable tendency to develop tumors of the parathyroid, pituitary, and entero-pancreatic endocrine tissues, is the consequence of a germline mutation in the MEN1 gene. Endocrine tumors in these patients result when the mutant MEN1 allele is accompanied by loss of the normal MEN1 allele. Recently it was reported that MEN1 patients also exhibit several cutaneous tumors, including multiple angiofibromas, collagenomas, and lipomas. The purpose of this study was to examine skin lesions from patients with MEN1 for allelic loss of the MEN1 gene. Skin lesions from five patients with MEN1 were examined using fluorescence in situ hybridization. Six angiofibromas, three collagenomas, and one lipoma showed allelic deletion of the MEN1 gene. Allelic deletion was not observed in a melanocytic nevus or acrochordon from patients with MEN1. It was also not observed in an angiofibroma from a patient with tuberous sclerosis. These results suggest that loss of function of the wild-type MEN1 gene product plays a role in the development of angiofibromas, collagenomas, and lipomas in patients with MEN1.