Familial medullary thyroid carcinoma (FMTC). Study of one family (treatment criteria).
OBJECTIVE
The nosology of familial medullary thyroid carcinoma (FMTC) has been described as a distinct pathology, genetically determined and with autosomal dominant transmission with a gene penetrance of almost 100%. The diagnosis of this morbid condition can be made if at least four members of the same family are affected by calcitonin-secreting C-cell carcinoma.


RESULTS
We report the analysis of a family in which FMTC was diagnosed between 1993 and 1998. Of the five patients we confirmed as being affected by FMTC, we were able to perform a prophylactic thyroidectomy in only one case. The high possibility of lymph-node metastasis at the time of clinical diagnosis (52-75%), and the high morbidity and radio-chemo-resistance to adjuvant therapies, indicate total thyroidectomy with central lymph-node dissection.


CONCLUSIONS
It appears that preventive lymphadenectomy does not substantially improve survival, while pre-clinical diagnosis is of greater importance than surgery in improving survival and preventing recurrence. Total preventive thyroidectomy has been recommended in all carriers of ret genetic defects, even in families at risk with mutations of the 618 or 620 codon, because the penetrance of FMTC approaches 100%, and a 100% accordance between presence of the disease and gene carrier status is reported. This procedure would therefore represent the only possibility of achieving a 100% cure in subjects affected by familial medullary thyroid carcinoma.
Carli
A F
AF
Surgical Science Department, Endocrine Surgery Unit, Siena, Italy.
Mariani
F
F
Di Cosmo
L
L
Giuli
R
R
Neri
A
A
D000293:Adolescent; D000328:Adult; D018276:Carcinoma, Medullary / Q000235:genetics* / Q000601:surgery*; D002648:Child; D029721:Drosophila Proteins; D005192:Family Health; D005260:Female; D005789:Genealogy and Heraldry; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000601:surgery*; D013965:Thyroidectomy
D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila