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 to determine whether they had multiple endocrine neoplasia associated with MEN 2B in the 5-year follow-up.

SUBJECTS AND METHODS

The family consisted of a 15 year old female complaining of burning eyes, examined ophthalmologically in 1992 and her mother and sister, who were examined later on in 1992. The proband and the mother were affected with multiple mucosal neuromas and visible corneal nerves. Pentagastrin-stimulated serum calcitonin levels, catecholamines, serum calcium and phosphate levels were measured. Molecular genetic studies were performed on the 2 affected members to look for the specific RET mutation seen in MEN 2B.

RESULTS

Endocrine neoplasia of the syndrome MEN 2B, medullary thyroid carcinoma, pheochromocytoma and hyperparathyroidism, were ruled out in the first examination and after 5-year follow-up. In the 2 cases no mutation at codon 918 for the RET proto-oncogene was found.

CONCLUSIONS

We consider that familial multiple mucosal neuromas are a highly distinctive entity of MEN 2B.