Medición rutinaria de calcitonina sérica en nódulos tiroideos / Routine serum calcitonin measurement in thyroid nodules

Existe mucha controversia sobre los beneficios de la medición de la calcitonina sérica (CT) durante la evaluación inicial de pacientes con nódulos tiroideos. El objetivo del estudio fue evaluar la identificación temprana del carcinoma medular de tiroides (CMT) a través de la medición rutinaria de CT sérica en una cohorte de Buenos Aires, Argentina. Se estudiaron consecutivamente a los pacientes con enfermedad nodular de la tiroides (n=1017). La CT se midió por quimioluminiscencia (valor normal: hasta 18 pg/ml en hombres y 12 pg/ml en mujeres). En dos pacientes, la hipercalcitoninemia se confirmó en mediciones repetidas. La aspiración con aguja fina con medición de CT en el líquido obtenido identificó la presencia del CMT. El estudio genético fue positivo en uno (mutación exón 14, Val804Met, CMT familiar). El otro presentó un polimorfismo (heterocigoto exón 13 L769L - heterocigoto exón 15 S904S). En ambos casos, la CT se normalizó 3 meses después de la cirugía y se mantuvo en valores normales después de 6 años de seguimiento. La medición rutinaria de la CT en nódulos tiroideos fue útil para detectar dos casos de CMT, uno de ellos esporádico y el otro familiar en la cohorte seguida. La prevalencia de CMT fue de 0.2%.

There is much controversy about the benefits of the use of serum calcitonin (CT) in the initial evaluation of patients with thyroid nodules. The objective of the study was to early identify medullary thyroid carcinoma (MTC) through the routine measurement of CT in thyroid nodular pathology in a large cohort of patients from Buenos Aires, Argentina. Consecutive patients with nodular thyroid disease (n=1017) were studied. CT was measured by chemiluminescence, normal value: up to 18 pg/ml in men and 12 pg/ml in women. In two patients, hypercalcitoninemia was confirmed in repeated measurements. Fine needle aspiration with CT measurement in the needle wash fluid identified MTC in nodules with citology abnormalities. The genetic study was positive in one patient (mutation exon 14, Val804Met, MTC familiar). The other presented a polymorphism (exon 13 L769L heterozygous - exon 15 S904S heterozygous). In both cases, CT was normalized 3 months after surgery and remained normal after 6 years of follow-up. The routine measurement of CT in thyroid nodular pathology was useful to detect two cases of MTC, one of them sporadic and the other familiar in this cohort. The prevalence of MTC was 0.2%.

Estudio del protooncogen RET en neoplasia endocrina multiple 2A y en carcinoma medular de tiroides familiar. Hallazgos clinico-patologicos en portadores asintomaticos / Study of RET protooncogene in multiple endocrine neoplasm 2A and in familial medullary thyroid carcinoma. Clinical pathological findings in asymptomatic carriers

Twenty five percent of the medullary thyroid carcinoma (MTC) is hereditary and 5% is familiar (FMTC), or considered as multiple endocrine neoplasia (MEN) type 2A (17%) or 2B (3%). These diseases are the result of the autosomic dominant inheritance of a mutation in the RET protooncogene, in one out of 12 different known codons. We analyzed 7 families (2 MEN 2A and 5 FMTC). Six mutations were detected in the most frequent codon, 634 (2 MEN 2A y 4 FMTC) and one family with FMTC presented a novel mutation: a transition T > C at codon 630, resulting a C630A change. Among 57 individuals studied, 25 (43.85%) presented the mutation. Seven (28%) were asymptomatic carriers, including 5 children aged 11 +/- 3.2 years. The children underwent total thyroidectomy. The histopathologic examination showed C cells hyperplasia and microcarcinoma focus in both lobes, even in the presence of normal, basal or pentagastrine stimulated, calcitonine levels. In conclusion, we describe a germine novel mutation in the RET protooncogene: C630A; and the corresponding findings of C-cell disease in gene mutated carriers that emphasize the importance of prophylactic thyroidectomy as soon as the molecular diagnosis is confirmed