Very early prophylactic thyroid surgery for infants with a mutation of the RET proto-oncogene at codon 634: evaluation of the implementation of international guidelines for MEN type 2 in a single centre.
OBJECTIVE
Genetic diagnosis available since 1993 established germinal mutations of the RET proto-oncogene at codon 634 as the main cause of inherited medullary thyroid carcinoma (MTC). International guidelines established in 1999 recommend that children with such mutations undergo a total thyroidectomy before age 5, with unspecified cervical neck dissection. Since 1993, only 41 of 275 thyroidectomies reported in RET 634 children were performed before age 5 (15%). The aim of this study was to evaluate the implementation of these guidelines in a single centre.


METHODS
Genetic diagnosis was proposed to the parents of all eight children born after 1992 from two RET 634 families. Total thyroidectomy was proposed before age 5 if the child carried a mutation.


RESULTS
Genetic diagnosis was performed in all the children (aged 1-3) and thyroidectomy in the five who carried a mutation (aged 2-5). Cervical lymph node dissection varied from lymphadenectomy of central and lateral compartments in the eldest child to pickings in the youngest. There was no permanent hypoparathyroidism or recurrent nerve paralysis. C-cell hyperplasia, medullary thyroid carcinoma and lymph node metastasis were present in 5/5, 3/5 and 0/5, respectively. Undetectable pentagastrin-stimulated CT levels were achieved and maintained postoperatively in all five children (average follow-up 3.6 years).


CONCLUSIONS
MEN 2 guidelines on thyroidectomy can be efficiently and safely implemented by a multidisciplinary team operating in a single centre. The lack of guidelines on cervical neck dissection remains a problem; this could be solved by determining an age under which this procedure would be deemed unnecessary.
Piolat
Christian
C
Department of Pediatric Surgery, University Hospital of Grenoble, France.
Dyon
Jean-François
JF
Sturm
Nathalie
N
Pinson
Stéphane
S
Bost
Michel
M
Jouk
Pierre-Simon
PS
Plantaz
Dominique
D
Chabre
Olivier
O
D014408:Biomarkers, Tumor / Q000097:blood; D002116:Calcitonin / Q000097:blood; D002675:Child, Preschool; D003062:Codon; D005260:Female; D005602:France; D019983:Guideline Adherence; D017408:Guidelines as Topic; D006801:Humans; D007223:Infant; D008297:Male; D018813:Multiple Endocrine Neoplasia Type 2a / Q000235:genetics* / Q000517:prevention & control* / Q000601:surgery; D009154:Mutation; D037981:Neck Dissection; D000090063:Proto-Oncogene Mas; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*; D012189:Retrospective Studies; D013965:Thyroidectomy
D014408:Biomarkers, Tumor; D003062:Codon; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D002116:Calcitonin; D051096:Proto-Oncogene Proteins c-ret