Neuromas and prominent corneal nerves without MEN 2B

Purpose - We studied a family composed of 2 members with the characteristic phenotype of the MEN 2B and without RET protooncogene mutations in order t o determine whether they had multiple endocrine neoplasia associated with M EN 2B in the 5-year follow-up. Subjects and methods - The family consisted of a 15 year old female complai ning of burning eyes, examined ophthalmologically in 1992 and her mother an d sister, who were examined later on in 1992. The proband and the mother we re affected with multiple mucosal neuromas and visible corneal nerves. Pent agastrin-stimulated serum calcitonin levels, catecholamines, serum calcium and phosphate levels were measured. Molecular genetic studies were performe d on the 2 affected members to look for the specific RET mutation seen in M EN 2B. Results - Endocrine neoplasia of the syndrome MEN 2B, medullary thyroid car cinoma, pheochromocytoma and hyperparathyroidism, were ruled out in the fir st examination and after 5-year follow-rep. In the 2 cases no mutation at c odon 918 for the RET proto-oncogene was Sound. Conclusions - We consider that familial multiple mucosal neuromas are a hig hly distinctive entity of MEN 2B.