Predictive DNA testing for multiple endocrine neoplasia 2: A therapeutic challenge of prophylactic thyroidectomy in very young children

Background: Patients with multiple endocrine neoplasia (MEN) type 2 are at risk for early medullary thyroid carcinoma (MTC). Recently, the cloning of the ret oncogene has made it possible to identify patients at risk for MEN 2 syndrome with a high degree of reliability before presenting any symptoms . Methods: Children of families with MEN 2 were screened genetically if one o f the parents was a known gene carrier of the RET proto-oncogene. If they w ere carriers, thyroidectomy was performed. Results: The authors report five children with MEN 2 who underwent prophyla ctic thyroidectomy irrespective of the results of calcitonin screening test s after genetic screening had shown that they were carrier of the RET proto -oncogene. Apart from a temporary hypocalcemia in one, the operations were uneventful. Pathology results showed MTC in three children of one family wi th MEN 2A at age 2, 3, and 6 yea rs. In two families with MEN 2B the thyroi dectomy specimen showed bilateral MTC in a 1-year-old and a 3-year-old chil d. Conclusions: These findings show that MTC occurs at very young age in child ren with MEN 2. The authors advocate performing prophylactic thyroidectomy in the first year of life in children with MEN 2B and at age 2 years in chi ldren with MEN 2A to obtain an optimal cure rate. Copyright (C) 1999 by W.B . Saunders Company.