PROPHYLACTIC THYROIDECTOMY IN 38 JUVENILES CARRIERS OF RET PROTO-ONCOGENE MUTATIONS: HISTOLOGICAL FINDINGS FINDINGS AND CLINICAL OUTCOME.

GABRIELA SANSO; ANA VIEITES; OSCAR ACHA; SILVANA MAGLIO; LEVIN GLORIA; SONIA IORCANSKY; MARTA BARONTINI

Lima

Congreso; XX REUNION DE LA SOCIEDAD LATINOAMERICANA DE ENDOCRINOLOGIA PEDIATRICA; 2008

Multiple endocrine neoplasia type 2 (MEN2) is an inherited disease caused by germline mutations in the RET proto-oncogen. Carriers of RET mutations are at risk for developing medular thyroid carcinoma (MTC) at young age. Detection of mutations of the RET proto-oncogen provides the basis for prophylactic thyroidectomy in children. In the present study, we report the results of prophylactic thyroidectomy in 38 carriers of RET mutations performed at ages from 17m to 21y (median 10y; males:22 ; females:16). Twenty seven carriers belonged to 15 families with MEN 2A and 11 to 3 families with FMTC. Level 2 mutations were harboured by 38 carriers: 36 in exon 11 codon 634, and 2 in exon 11 codon 611. Histology was normal only in a 4-year-old carrier. The other 37 carriers had C-cell hyperplasia and in 30 of them MTC was present. MTC was unilateral in 13 and bilateral in 17.In 4/17 bilateral, multifocal MTC was found and one of them presented regional lymph node metastases. Preoperative basal calcitonin levels were increased in 16/38 children: in 3/9 younger than 5 y., in 3/15 with ages between 5 and 10 y. and in 10/16 of 11 to 21y. In all patients under 10 y. calcitonin levels dropped to normal after surgery while they remained high in 3/10 patients older than 10 y. All patients are alive followed up between 1 and 25 y. post thyroidectomy. No patient presented any other associated endocrine neoplasia indicating that MTC is the first manifestation of MEN2A in juvenile carriers. The results of this study emphasize the importance of early screening and preventive thyroidectomy in children at risk to develop MTC.