PROPHYLACTIC THYROIDECTOMY IN 75 CHILDREN AND ADOLESCENTS WITH HEREDITARY MEDULLARY-THYROID CARCINOMA - GERMAN AND AUSTRIAN EXPERIENCE

When mutations of the RET proto-oncogene were found in 1993 to account for hereditary medullary thyroid carcinoma (MTC), surgeons obtained t he opportunity to operate on patients prophylactically (i.e., at a cli nically asymptomatic stage). Whether this approach is justified, and, if so, when and to which extent surgery should be performed remained t o be clarified. A questionnaire was sent to all surgical departments i n Germany and Austria. All of the patients who fulfilled the following criteria were enrolled: (1) preoperatively proved RET mutation; (2) a ge less than or equal to 20 years, (3) clinically asymptomatic thyroid C cell disease; and (4) TNM classification pTO-1/pNX/pNO-1/MO. Sevent y-five patients mere identified, and fifteen mutations were detected i n six codons. Two adolescents had unilateral pheochromocytomas as part of the multiple endocrine neoplasia II (MEN-PI) syndrome. No hyperpar athyroidism was noted. All patients underwent total thyroidectomy, and 57 patients went on to have lymph node dissection. Parathyroid glands were removed in 34 patients and autografted in 11. Histopathology rev ealed MTC in 46 patients (61%, youngest 4 years); C cell hyperplasia ( CCH) only was detected in the other 29 patients. Three patients had ly mph node metastases (LNMs) the youngest being age 14 Sears. Calcitonin levels were not useful for differentiating between CCH and MTC, but i n all patients with LNMs at least the stimulated calcitonin levels mer e assayed. After surgery, five patients (6.7%) sustained permanent hyp oparathyroidism, and one patient (1.3%) had a permanent unilateral rec urrent nerve palsy. All but three patients (96%) were biochemically cu red. In conclusion, prophylactic total thyroidectomy can be performed safely in experienced centers. We recommend prophylactic total thyroid ectomy at age 6. Cervicocentral lymph node dissection should be includ ed when calcitonin levels are elevated or if patients are older than 1 0 years. Bilateral lymph node dissection should be performed if LNMs a re suspected or when patients with elevated calcitonin are older than 85 years.