The syndrome of multiple aucosal neuromas and medullary thyroid carcinoma in childhood. Importance of recognition of the phenotype for the early detection of malignancy.

Recognition of the syndrome of OF MMN can identify individuals at risk for the early appearance of MTC. Three such patients are described. Each had the characteristic neuromas and facies, present since infancy. In each, MTC was found in childhood. In the last two patients, the diagnosis was made because of elevated serum CT concentrations. Venous drainage from the tumor, as well as tumor tissue itself, contained high levels of CT. Prompt recognition of persons with MMN is essential for proper investigation and treatment of the associated MTC.