Tiroides Ectópica Lingual: caso Clínico / Lingual Ectopic Thyroid: a clinical case

La tiroides ectópica lingual es una patología muy poco frecuente, producida por la detención en el descenso normal de la glándula durante el desarrollo embrio-nario. La localización lingual de tejido tiroideo es la más común entre las tiroides ectópicas o aberrantes. Esta enfermedad puede ser asintomática pero, cuan-do los signos y síntomas están presentes, guardan estrecha correlación con la localización de la lesión y son proporcionales a su tamaño. El diagnóstico debe realizarse clínicamente y con el complemento de es-tudios por imágenes y endocrinológicos. En los aná-lisis de laboratorio se debe incluir dosaje de las hor-monas TSH, T4 libre y T3, vinculadas con la función tiroidea. Las biopsias deben evitarse ya que causan desequilibrio en la producción hormonal de la glándu-la y peligro de profusas hemorragias. En este artículo se desarrolla una descripción de las generalidades de la tiroides ectópica lingual, y se presenta un caso clínico de un niño con un tumor lingual, que fue deri-vado por su médica pediatra a cirugía para realizar una biopsia. Asimismo, se comenta la importancia que tiene para el odontólogo conocer esta patología a fin de poder evitar sus posibles complicaciones (AU)

Lingual thyroid is a rare disorder produced by a failure in the descent of thyroid gland to its normal position during embryological development. Lingual localization of thyroid tissue is the most common among the ectopic or aberrant thyroids. This condition can be asymptomatic, although when symptoms take place, they are connected to the lesion location and depend on its size. Diagnosis should be made clinically and complemented with imaging and endocrine studies. Laboratory analysis must include dosage of TSH, free T4 and T3, thyroid function-linked hormones. Due to the possible imbalance in the gland hormone production and the risk of massive bleeding, biopsy should be avoided. In this article, a brief description of lingual ectopic thyroid generalities is developed and a clinical case of a 7-years old child is provided. Additionally, dentistry importance of knowing this condition is commented, in order to prevent its possible complications (AU)

Impact of the reduction in TSH cutoff level to 6 mIU/L in neonatal screening for congenital hypothyroidism in Santa Catarina: final results

ABSTRACT Oubjective: To assess the implications of changing the cutoff level of TSH from 10 to 6 mIU/L. Subjects and methods: The study population was constituted by 74.123 children screened for congenital hypothyroidism by the National Screening Program in Santa Catarina, from March 2011 to February 2012. The cutoff of TSH was 6 mIU/L. If TSH between 6-10 mIU/L, the newborn was recalled for a second TSH measurement on filter paper. If TSH > 6 mIU/L in the second sample, the child was sent for medical evaluation. In children with normal topic thyroid, levothyroxine was suspended for 1 month at the age of 3 years for identification of the etiology and evaluation of the need to continue treatment. Results: Among the children screened, 435 were recalled for presenting TSH between 6 and 10 mIU/L in the first sample, 28 remained TSH > 6 mIU/L in the second sample. Among these, 11 had a final diagnosis of dyshormonogenesis, two of ectopic thyroid, two of thyroid hypoplasia and one of transient hypothyroidism. Ten children presented normal TSH levels on the first medical evaluation and two lost follow-up. Conclusion: A decrease in the TSH cutoff level from 10 to 6 mIU/L in a neonatal screening program for congenital hypothyroidism reduced the number of false-negative results, increasing the sensitivity of the test, but increased the number of false-positive results and recalls. Since a TSH cutoff level of 6 mIU/L detects thyroid function abnormalities requiring treatment, the adoption of this cutoff level is justified.

Caso Clínico: Tiroides Lingual Ectópica en Paciente Adulta Hipotiroidea. Diagnóstico Casual por Tomografía Computarizada. / Clinical Case: Ectopic Lingual Thyroid in Adult Hypothyroid Patient. Casual Diagnosis by Computed Tomography.

Introducción: Los casos de tiroides ectópica localizados en la base de la lengua son anormalidades congénitas raras y difíciles de diagnosticar. Razón de presentación del caso. Caso Clínico: El caso corresponde a una mujer de 41 años con tiroides en base de la lengua diagnosticada incidentalmente con tomografía computarizada (TC), con antecedentes de hipotiroidismo y cáncer de mama derecha. Al examen físico de cuello no se palpa glándula tiroidea ni se observa masa o protuberancia en cavidad bucal. Por control del cáncer de mama, se solicita tomografía por emisión de positrones (PET) y ecografía de cuello, reportándose captación del radiofármaco en la región cervical anterior y superior de cuello, y ausencia de tejido glandular tiroideo a nivel habitual, respectivamente. Por cuanto, se realiza TC simple y contrastada observándose a nivel de la raíz de la lengua una imagen nodular hipercaptante que mide 23x20x20 mm, bien definida, contornos regulares, no infiltra tejidos adyacentes, impronta luz de la orofaringe, sin individualizar la glándula tiroides a nivel habitual, corroborando así el diagnóstico de tiroides ectópica lingual. Conclusión: El diagnóstico de tiroides ectópica en paciente adulto hipotiroideo es raro, por lo que debe considerarse la realización de TC si al examen físico y ecográfico no es palpable ni observable

Introduction: Cases of ectopic thyroid located at the base of the tongue are rare and difficult to diagnose congenital abnormalities. Reason for presenting the case. Clinical case: The case corresponds to a 41-year-old woman with thyroid based on the tongue diagnosed incidentally with computed tomography (CT), with a history of hypothyroidism and right breast cancer. On the physical examination of the neck, the thyroid gland is not palpated, and no mass or bump is observed in the oral cavity. For breast cancer control, positron emission tomography (PET) and neck ultrasound are requested, radiopharmaceutical uptake is reported in the anterior and upper cervical neck region, and absence of thyroid glandular tissue at the usual level, respectively. As a simple and contrasted CT scan, a hypercapting nodular image measuring 23x20x20 mm, well defined, regular contours is observed at the root of the tongue, does not infiltrate adjacent tissues, oropharynx light imprint, without individualizing the thyroid gland to usual level, thus corroborating the diagnosis of lingual ectopic thyroid. Conclusion: The diagnosis of ectopic thyroid in an adult hypothyroid patient is rare, so CT should be considered if the physical and ultrasound examination is not palpable or observable.

Mutation screening in the genes PAX-8, NKX2-5, TSH-R, HES-1 in cohort of 63 Brazilian children with thyroid dysgenesis

ABSTRACT Objective: To evaluate the candidate genes PAX-8, NKX2-5, TSH-R and HES-1 in 63 confirmed cases of thyroid dysgenesis. Subjects and methods: Characterization of patients with congenital hypothyroidism into specific subtypes of thyroid dysgenesis with hormone levels (TT4 and TSH), thyroid ultrasound and scintigraphy. DNA was extracted from peripheral blood leukocytes and the genetic analysis was realized by investigating the presence of mutations in the transcription factor genes involved in thyroid development. Results: No mutations were detected in any of the candidate genes. In situ thyroid gland represented 71.1% of all cases of permanent primary congenital hypothyroidism, followed by hypoplasia (9.6%), ectopia (78%), hemiagenesis (6.0%) and agenesis (5.5%). The highest neonatal screening TSH levels were in the agenesis group (p < 0.001). Conclusions: Thyroid dysgenesis is possibly a polygenic disorder and epigenetic factors could to be implicated in these pathogeneses.

Tiroides ectópica dual hiperfuncionante: abordaje quirúrgico dual / Dual hyperfunctioning thyroid ectopia: dual surgical approach

RESUMEN Paciente de 36 años en tratamiento de leucemia mieloide crónica con nilotinib a quien se le diagnostica hipertiroidismo por síntomas clínicos y exámenes de laboratorio. Se inicia tratamiento con metimazol más propanolol. Los estudios imagenológicos muestran un tejido ectópico tiroideo cervical infrahiodeo lateralizado a la izquierda y un nódulo en la base de la lengua. Presentó toxicidad hepática atribuida al tratamiento por lo que se decide extirpación quirúrgica de tiroides ectópica dual. Por la edad de la paciente y preocupación acerca del resultado estético, se realiza una tiroidectomía videoasistida por via axilar de la tiroides ectópica cervical y una resección transoral de la tiroides ectópica lingual. La patología confirma tejido tiroideo en ambas localizaciones sin signos de malignidad. La paciente se recuperó sin complicaciones y sin cicatriz cervical.

ABSTRACT A 36-year-old female patient with chronic myeloid leukemia being treated with nilotinib who was diagnosed with hyperthyroidism both on clinical and laboratory examination is presented. Imaging studies found left lateralized ectopic thyroid tissue of infrahyoid localization and a nodule at the base of the tongue. Hepatic toxicity was attributed to medical treatment, surgical removal of the dual thyroid ectopia was proposed. Due to the patients age and cosmetical concerns, a minimally invasive surgery was undertaken thru a video assisted transaxillary thyroidectomy for the cervical thyroid ectopia and a video assisted trans oral approach for the lingual thyroid ectopia. Post op pathology confirmed thyroid tissue at both locations and also excluded malignancy. The patient fully recovered without any complicaction and witout a residual cervical scar.

Coexistence of resistance to thyroid hormone and ectopic thyroid: ten-year follow-up

SUMMARY Resistance to thyroid hormone (RTH) coexisting with ectopic thyroid is rare. Here we report a case of RTH with ectopic thyroid. A ten-year-old girl had been misdiagnosed as congenital hypothyroidism and treated with levothyroxine since she was born. Ten-year follow-up showed that the elevated thyrotropin was never suppressed by levothyroxine and no signs indicating hyperthyroidism or hypothyroidism despite elevated FT3 and FT4 levels. Therefore the girl developed no defects in physical and cognitive development. Pituitary adenoma was excluded by magnetic resonance imaging. Ultrasonography did not find the thyroid gland in the normal place, while the thyroid scan found a large lingual thyroid gland. The octreotide inhibition test showed a reduction in thyrotropin by 41.98%. No mutation was detected in the thyroid hormone receptor (THR) β, THRα, thyrotropin receptor (TSHR), and GNAS1 genes. To our knowledge, it is an interesting RTH case coexisting with lingual thyroid.

Importance of ectopic thyroid tissue detected in the midline of the neck: single center experience

Objective Ectopic thyroid tissue (ETT) is a rare abnormality of the thyroid gland and the true prevalence and importance is not known. The aim of this study was to evaluate ultrasonography (US) guided fine needle aspiration biposy (FNAB) results, sonographic features, and frequency of ETT detected in the midline of the neck. Subjects and methods Five thousand five hundred and twenty outpatients who were referred to our thyroid clinic between September 2010 and April 2012 and underwent thyroid US, were retrospectively analyzed. Patients with ETT, detected in the midline of the neck in US were included in the study. Thyroid functions, sonographic features, and US guided FNAB results were evaluated. Results There were 81 (81.8%) female and 18 (18.2%) male patients with a mean age of 50.9 ± 11.7. The ETT in the midline was present in 1.79% (99/5,520) of the patients. In the majority of the patients, benign sonographic features (isoechoic, regular margin, type 1 vascularization) were detected. There were 92 (92.9%) patients with a previous history of thyroidectomy and all were histopathologically benign. In 7 (7.1%) patients, there was no history of thyroid operation. FNAB results of ETT were benign. Conclusion This study evaluated the importance of ETT detected incidentally in the midline of the neck. Especially in patients with a history of thyroidectomy, the thyroid masses in the midline of the neck can be found as incidental with imaging methods. Our results suggests that the incidence of malignancy in this group is much lower than orthotopic thyroid nodules and they are often benign.

Abordaje inmunológico del síndrome por deleción 22q11 / Immunological approaches to 22q11 deletion syndrome

El síndrome por deleción 22q11 (SD22q11) es el síndrome por deleción cromosómica más frecuente en humanos y se caracteriza por la tríada clínica que incluye cardiopatía congénita, hipocalcemia e inmunodeficiencia primaria. El 85-90% de los pacientes tienen microdeleciones en el cromosoma 22q11.2. Tomando como punto cardinal la cardiopatía congénita, se diseñó una estrategia para tamización y diagnóstico de SD22q11 con énfasis en la evaluación inmune. Es imprescindible realizar una historia clínica detallada y, posteriormente, un análisis cuantitativo y funcional de las subpoblaciones de linfocitos en sangre periférica para clasificarlo en SD22q11 completo (<1%) o parcial (95-99%) e instaurar las pautas de tratamiento en aspectos como: aislamiento del paciente, vacunación, profilaxis contra microorganismos oportunistas, uso de productos sanguíneos irradiados y reconstitución inmunológica. Sin embargo, el abordaje del paciente debe ser multidisciplinario para detectar y prevenir complicaciones a largo plazo que pueden ser graves, especialmente en los pacientes con SD22q11 completo.

In humans, 22q11 deletion syndrome (22q11DS) is considered the most common chromosome deletion syndrome. It is characterised by a clinical triad that includes congenital heart disease, hypocalcaemia and primary immunodeficiency. Approximately 85-90% of patients with this syndrome exhibit microdeletions in chromosome 22q11.2. Using congenital heart disease as a starting point, we designed a strategy for the screening and diagnosis of 22q11DS with an emphasis on immunological evaluation. A detailed clinical history and the subsequent quantitative and functional analyses of the lymphocyte subpopulations in the peripheral blood is crucial to classify as complete (<1%) or partial (95-99%) the disease and to guide clinicians in terms of patient isolation, vaccination, prophylaxis for opportunistic infections, use of irradiated blood products and immunological reconstitution. However, multidisciplinary care is necessary to detect and prevent long-term complications that could be severe, particularly in cases of complete 22q11DS.

Estudo clínico, genético e molecular de pacientes com Disgenesia Tireoidiana

INTRODUÇÃO: Hipotireoidismo Congênito (HC), é uma das doenças metabólicas mais comuns na infância com incidência de 1:3.000 a 1:4.000 recém-nascidos. Um grupo de doenças relacionadas às alterações no desenvolvimento da tireoide, denominadas disgenesias tireoidianas (DT), responsabiliza-se por aproximadamente 85% de todos os casos de HC, sendo sua patogênese pouco conhecida. OBJETIVOS: Geral: Caracterização clínica e genética de pacientes com HC diagnosticados com disgenesia tireoidiana. Específicos: 1. Caracterizar clínica dos indivíduos com HC em acompanhamento na APAE/Salvador (Associação de Pais e Amigos dos Excepcionais); 2. Avaliar a existência de associação entre malformações tireoidianas e malformações cardiacos; 3. Pesquisar polimorfismos e mutações nos genes candidatos: PAX8, TSH-R, NKX2.5 e HES1, em pacientes diagnosticados com disgenesia tireoidiana; 4. Pesquisar o gene TSH-R numa coorte de pacientes com HC diagnosticados no programa de triagem neonatal da França. METODOLOGIA: Até o ano de 2016, 1.188 crianças foram diagnosticadas com HC e 773 estão em acompanhamento. Duzentos e dezoito crianças confirmadas com HC foram caracterizadas clinicamente através de testes de função da tireoide (TT4 e TSH), ultrassonografia e cintilografia, seguidas de dosagem de tireoglobulina. Toda a região codificantes dos genes PAX8, TSH-R, NKX2.5 e HES1 incluindo íntrons e éxons foram amplificados a partir do DNA genômico através da PCR (Reação em cadeia da Polimerase) utilizando-se técnicas padrão seguida de Sequenciamento direto. RESULTADOS: Sessenta e três pacientes foram diagnosticados com DT e 155 com glândula tópica normal. Hipoplasia representou 33,4% dos casos de DT, agenesia 19%, ectopia 27% e hemiagenesia 20,6%. Altos concentrações de TSH no teste do pezinho foram detectados no grupo das agenesias seguido das hipoplasias. Na análise genética/molecular, 31 (49,2%) dos pacientes foram identificados com o polimorfismo p.D727E em heterozigose e 4 (6,4%) em homozigose, no gene TSH-R; 4/63 pacientes tiveram o polimorfismo p.P52T em heterozigose; 14/63 apresentaram a variante polimórfica p.N181N e 2/63 apresentaram a substituição sinônima conhecida p.L645L, todos no gene TSH-R. o polimorfismo p.Glu21 foi encontrado em 54% dos pacientes e p.Gln181 encontrado em 1 paciente no gene NKX2.5. Nenhuma alteração foi encontrada no gene HES1, bem como em PAX8. CONCLUSÕES: Este é o primeiro estudo realizado na população de HC no Estado da Bahia. Análises clínicas revelaram um padrão distinto entre os subgrupos da DT quando comparados com glândula normal; 6 polimorfismos já descritos foram encontrados em dois genes candidatos. Nenhuma mutação patogênica foi encontrada. A descrição fenotípica é essencial para a correta avaliação genética e os mecanismos nela implicados, além de utilizados para predição da gravidade do HC. A identificação de novos genes ou eventos moleculares que controlam a função tireoidiana pós-natal seria de grande utilidade no esclarecimento das DT

INTRODUCTION: Congenital hypothyroidism (CH), is the most common metabolic diseases in childhood with incidence of 1: 3000-1: 4000 newborns. A group of diseases related to alterations in the development of the thyroid, called thyroid dysgenesis (TD), is responsible for approximated 85% of all HC cases, and the majority has unknown pathogenesis. OBJECTIVES: General: clinical and genetic characterization of CH patients diagnosed with TD. Specific: 1. CH clinical characterization in individuals followed at APAE/Salvador; 2. evaluating the association between thyroid abnormalities and other abnormalities or syndromes; 3. search polymorphisms and mutations in known candidate genes for TD: PAX8, TSH-R, NKX2.5 and HES1; 4. XX METHODS: Until the year 2016, 1.188 children were diagnosed for CH and 773 were actually follow in APAE-Salvador. A continuous series of 218 children with confirmed HC were characterized clinically through thyroid function tests (TT4 and TSH), thyroid ultrasound and scintigraphy, followed by serum thyroglobulin measurement. The entire coding region of the candidate genes (PAX8, TSH-R, NKX2.5 and HES1), including exon/intron boundaries, was amplified from genomic DNA by polymerase chain reaction (PCR) using standard techniques, followed by direct sequencing. Results: Sixty-three patients were diagnosed with DT and 155 with in situ thyroid gland (ISTG). Hypoplasia represented 33,4% of all cases of DT, agenesis (19%), ectopy (27%) and hemiagenesis (20,6%). The higher screening TSH levels was in the agenetic group followed by hypoplasia. In the genetic/molecular analysis, 31 (49,2%) patients were identified with a polymorphism of TSH-R gene (p.D727E); 4/63 patients had a heterozygous p.P52T; 14/63 patients showed p.N187N polymorphic variants of the gene; and 2/63 patients presented a known p.L645L synonimous substitution. The polymorphism p.Glu21was found in 54% of patients, and p.Gln181 found in only one patient in the NKX2.5 gene. None alteration was detected in HES1 gene. CONCLUSIONS: This is the first CH population-based study in State of Bahia, Brazil. Clinical analysis revealed distinct hormonal patterns in DT subgroup when compared with ISTG, with only 6 known polymorphisms identified in few cases of TD in TSH-R, PAX8, NKX2.5 and HES1 genes. No mutation was found in a candidate genes studied. A detailed description of phenotype might be essential to target the correct genetic and mechanism implicated, and useful to predict CH severity. The identification of additional genes or molecular events controlling early postnatal thyroid function would be helpful.

The c.63A>G polymorphism in the NKX2.5 gene is associated with thyroid hypoplasia in children with thyroid dysgenesis

Objective To search for genetic alteration in NKX2.5 gene in patients presenting both congenital heart disease (CHD) and TD. Subjects and methods Individual phenotypes were carefully analyzed in 86 children with thyroid dysgenesis (TD) using thyroid function tests, scintigraphy, ultrasound and echocardiography. DNA was extracted and NKX2.5 gene coding region was amplified by polymerase chain reaction (PCR) and sequenced. Results CHD were found in 8.1% of patients with TD. The mutation screening revealed two known polymorphisms in patients with isolated TD or TD associated with CHD. None of them are predicted to result in codon change in conserved domain. The c.63A>G polymorphism was detected in 54/86 patients (49 with isolated TD and 5 with TD combined with CHD). There was a significant association of c.63A>G polymorphism with hypoplasia (p < 0.036). The c.541G>A polymorphism was observed in only one patient with isolated thyroid hypoplasia. Conclusion NKX2.5 mutations were not found. The c.63A>G polymorphism might be associated with thyroid hypoplasia.

Hipoplasia tímica en un niño con fibrosis quística / Thymic hypoplasia in an infant with cystic fibrosis

La fibrosis quística es la enfermedad autosómica recesiva más frecuente en poblaciones caucásicas; en Cuba, uno de cada 5 000 recién nacidos están afectados. En 1989 fue clonado el gen regulador de la conductancia transmembranal de la fibrosis quística e identificada su mutación principal, F508del. Desde entonces han sido descritas más de 1 300 mutaciones diferentes en este gen. El timo es el principal órgano de maduración de los linfocitos T, es relativamente grande y muy activo al nacer. El síndrome de Di George, descrito en 1965, incluye varias malformaciones congénitas y déficit inmunológico, principalmente de células T por hipoplasia del timo. Actualmente existen criterios definitivos, probables y posibles que diagnostican la entidad y se reportan síndromes completos y parciales en dependencia de los síntomas y signos presentes en el enfermo; sin embargo, puede observarse hipoplasia severa del timo en pacientes sin diagnóstico de Di George. Se presenta el caso de un paciente pediátrico en el que se define el diagnóstico de fibrosis quística por estudios moleculares y se identifica como homocigótico para la mutación F508del con hipoplasia severa del timo

Cystic fibrosis is the most common autosomal recessive disease in Caucasian populations; in Cuba, one in 5 000 newborns are affected. In 1989, the conductance regulator gene for cystic fibrosis transmembrane was cloned and its main mutation F508del was identified. Since then, over 1 300 different mutations in the gene have been described. The thymus is the primary organ of T cell maturation, is relatively large and very active at birth. DiGeorge syndrome, described in 1965, includes several birth defects and immune deficits, mainly of T cells by thymic hypoplasia. Currently, definitive, probable and possible criteria to diagnose the entity exist as well as reports of full and partial syndromes depending of symptoms present in the patient; nevertheless, severe thymic hypoplasia can be observed in patients without diagnosis of Di George. We report the case of a pediatric patient with diagnosis of cystic fibrosis by molecular studies identified as homozygous for the mutation F508del with severe thymic hypoplasia

Frecuencia de disfunción tiroidea en gestantes / Frequency of thyroid dysfunction in pregnant women

Objetivo. Determinar la frecuencia de disfunción tiroidea en las gestantes. Material y Métodos. El estudio descriptivo y prospectivo se hizo en 138 gestantes (entre 6 y 40 semanas de gestación), aparentemente sanas, seleccionadas aleatoriamente y atendidas en el consultorio externo de Ginecología y Obstetricia del Hospital Nacional Arzobispo Loayza (HNAL), Lima, durante diciembre de 2012. A aquellas con niveles elevados de TSH para su respectivo trimestre gestacional (TSH > 2,5 mUI/L durante el primer trimestre y TSH > 3,0 mUI/L durante el segundo o tercer trimestre) se les determinó los niveles de T4L y anticuerpos anti-TPO; y, a aquellas con niveles disminuidos de TSH se les determinó T4L, T3L y anti-TPO. El hipotiroidismo subclínico fue definido como niveles elevados de TSH para su respectiva edad gestacional y niveles normales de T4L. El hipertiroidismo subclínico fue definido como niveles disminuidos de TSH y normales de T4L y de T3L. La disfunción tiroidea autoinmune fue definida como niveles elevados y/o suprimidos de TSH y elevados de anticuerpos anti-TPO (> 30 AU/mL). Resultados. La frecuencia de hipotiroidismo subclínico durante el embarazo fue 13,76% y de hipertiroidismo subclínico fue 1,45%. La frecuencia de disfunción tiroidea autoinmune fue 2,17%. Conclusiones. Se encontró una alta frecuencia de hipotiroidismo subclínico en la población estudiada, por lo que se sugiere el tamizaje universal mediante la determinación de TSH para el descarte de hipotiroidismo en gestantes aparentemente sanas. La frecuencia de disfunción tiroidea autoinmune encontrada no difirió de la reportada en la literatura.

Objective. Determine the frequency of thyroid dysfunction in pregnant women. Material and MethOds. A descriptive and prospective study was carried out in 138 apparently healthy and randomly selected pregnant women (between 6 and 40 weeks of gestational age) attending tn the outpatient GO department during December of 2012. Serum FT4 and anti-TPO antibodies titers were assessed when TSH levels were above the upper normal limit of 2,5 mIU/L in the first trimester or 3 mIU/L in the second or third trimesters. Serum FT4, FT3 and anti-TPO antibodies were assessed when TSH levels were below the lower normal limit. Subclinical hypothyroidism was defined as elevated TSH levels combined with normal FT4 levels. Subclinical hyperthyroidism was defined as a serum TSH level below the normal lower limit of reference range in combination with normal FT4 and FT3 levels. Autoimmune thyroid dysfunction during pregnancy was defined as an elevated serum TSH levels combined with elevated anti-TPO antibodies titers (> 30 AU/mL). Results. The frequency of subclinical hypothyroidism was 13,76% and subclinical hyperthyroidism was 1,45%. And, the frequency of pregnant women who had autoimmune thyroid dysfunction was 2,17%. Conclusions. We found a high frequency of subclinical hypothyroidism so we suggest an universal screening by determination of serum TSH in apparently healthy pregnant women in order to rule out hypothyroidism. The found frequency of autoimmune thyroid dysfunction did not differ from that reported in the literature.

Hipotiroidismo congénito secundario a hipoplasia tiroidea detectado en edad adulta / Congenital hypothyroidism secondary to thyroid hypoplasia detected in adulthood

La ubicación anatómica de la glándula tiroidea y su biosíntesis hormonal están reguladas por la expresión de ciertos genes, cuya alteración puede conducir a las denominadas disgenesias tiroideas: agenesia, ectopía e hipoplasia, así como a las variantes dishormonogenéticas. Se presenta el caso de una paciente con retraso mental y diagnóstico de hipotiroidismo realizado en la edad adulta. Las determinaciones bioquímicas confirmaron el diagnóstico de hipotiroidismo no autoinmune. Este caso representa la evolución prolongada de una hipofunción tiroidea, que cursó en forma solapada y no diagnosticada durante 53 años de vida, con secuelas relevantes de esta deficiencia al momento del diagnóstico. La terapia exógena logró mejorías evidentes en la signo sintomatología, pero no revirtió el presunto daño neurológico atribuible a la falta de hormona tiroidea necesaria durante el desarrollo fetal. En la necropsia realizada se encontró escaso tejido tiroideo cervical correspondiente a hipoplasia tiroidea eutópica. El hallazgo de un remanente tiroideo menor a 1 cm permite explicar la supervivencia de la paciente hasta una edad avanzada.

The anatomical location of the thyroid gland and its hormone byosinthesis are regulated by the expression of certain genes, whose disruption leads to the so-called thyroid dysgenesis: agenesis, ectopia and hypoplasia, and to dyshormonogenesis. We present the case of a patient with mental retardation and hypothyroidism whose diagnosis was made in adulthood. Biochemical determinations confirmed the diagnosis without evidence of thyroid autoimmunity. This patient represents the extended evolution of a thyroid hypofunction, which lasted in an unsuspected way for 53 years, with important consequences of this deficiency at diagnosis. Exogenous therapy achieved great improvement in clinical symptoms, but did not reverse the neurological damage attributable to the lack of thyroid hormone necessary for fetal development. The necropsy revealed little thyroid tissue in the neck corresponding to eutopic thyroid hypoplasia. The discovery of a remaining thyroid of less than 1 cm justified the patient survival up to old age.

Hipotireoidismo congênito: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia / Congenital hypothyroidism: recommendations of the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism

O hipotireoidismo congênito (HC) é o distúrbio endócrino congênito mais frequente, com incidência variando de 1:2.000 a 1:4.000 crianças nascidas vivas e uma das principais causas de retardo mental que pode ser prevenida. Os Programas de Triagem Neonatal para a doença permitem a identificação precoce dos afetados e seu tratamento de modo a evitar as complicações da falta do hormônio. A maioria dos casos de hipotireoidismo congênito é decorrente de disgenesias tireoidianas (85%), entre elas a ectopia, hipoplasia ou agenesia tireoidianas, e os demais resultam de defeitos de síntese hormonal. As crianças afetadas (> 95%) geralmente não apresentam sintomas sugestivos da doença ao nascimento. Os sintomas e sinais mais comuns são: icterícia neonatal prolongada, choro rouco, letargia, movimentos lentos, constipação, macroglossia, hérnia umbilical, fontanelas amplas, hipotonia e pele seca. Várias estratégias são utilizadas para a triagem do HC. No Brasil, esta é obrigatória por lei e geralmente é feita com a dosagem de TSH em sangue seco coletado do calcanhar. A idade recomendada para sua realização é após as 48 horas de vida até o quarto dia. A confirmação diagnóstica é obrigatória com as dosagens de TSH e T4 livre ou T4 total.

Congenital hypothyroidism (CH) is the most common congenital endocrine disorder, with an incidence of 1:2,000 to 1:4,000 live births and it is a leading preventable mental retardation. Neonatal Screening Programs allow early identification of the disease and the adequate treatment of affected children can avoid the complications related to deprivation of the hormone. Most cases of primary congenital hypothyroidism (85%) are due to thyroid dysgenesis (ectopia, hypoplasia or agenesis) while the remaining result from defects in hormone synthesis. Affected children (> 95%) usually have no symptoms suggesting the disease at birth. The most frequent symptoms and signs are prolonged neonatal jaundice, hoarse cry, lethargy, slow movements, constipation, macroglossia, umbilical hernia, large fontanelle, hypotonia and dry skin. Around the world, various strategies are used for the screening of the CH. In Brazil, screening for CH is mandatory by law and usually done by serum TSH in dried blood collected from the heel. The recommended age for performing this test is after 48 hours of life until the 4th day. Diagnostic confirmation is required dosing TSH and free T4 or total T4 in serum.

Programa de Triagem Neonatal para hipotireoidismo congênito de Santa Catarina, Brasil: avaliação etiológica no primeiro atendimento / Newborn Screening Program for congenital hypothyroidism of the State of Santa Catarina, Brazil: etiological investigation in the first visit

OBJETIVO: Avaliar a etiologia, no primeiro atendimento, dos casos de hipotireoidismo congênito primário (HCP) identificados pelo Programa de Triagem Neonatal de Santa Catarina entre julho de 2007 e junho de 2009. SUJEITOS E MÉTODOS: Estudo prospectivo com 45 pacientes com HCP confirmado. Para o diagnóstico etiológico, eram realizados na primeira consulta: anamnese, exames físico e complementares (TSH, tiroxina livre, tireoglobulina, idade óssea, ultrassonografia de tireoide). RESULTADOS: Estabeleceu-se o diagnóstico etiológico na primeira consulta em 53,33%. Disgenesia representou 51,11%, sendo 20% hipoplasia, 13,3% atireose e 17,7% ectopia; e 2,2% foram diagnosticados com disormoniogênese. Hérnia umbilical foi o sinal mais prevalente (48,89%) e 20% não apresentaram manifestação clínica. Aqueles com disgenesia apresentaram diferença significativa (p < 0,05) pela via de parto cesária, idade óssea atrasada e TSH sérico muito elevado. CONCLUSÕES: A abordagem diagnóstica realizada no primeiro atendimento determina a etiologia do HCP em 53,3% dos casos. A metade dos pacientes apresenta disgenesia tireoidiana. Arq Bras Endocrinol Metab. 2012;56(9):627-32.

OBJECTIVE: To evaluate the etiology of primary congenital hypothyroidism (PCH) identified in the Newborn Screening Program from the state of Santa Catarina, Brazil, from July 2007 to June 2009 in the first visit. SUBJECTS AND METHODS: A prospective study was performed in 45 patients with PCH. For the etiological diagnosis, history, physical examination, and additional tests (TSH, free thyroxine, thyroglobulin, bone age assessment, thyroid ultrasound) were carried out in the first visit. RESULTS: The etiology was established in the first visit in 53.3% of cases. Thyroid dysgenesis represented 51.11% of the cases, from which 20% showed hypoplastic thyroid, 13.3% showed athyreosis, and 17.7% showed ectopic glands; 2.2% were diagnosed with dyshormonogenesis. Umbilical hernia was the most prevalent sign (48.89%) and 20% had no clinical manifestations. Patients with dysgenesis showed significant differences (p < 0.05) in terms of cesarean section delivery, delayed bone age, and very high serum TSH. CONCLUSIONS: The diagnostic approach used at first visit for PCH patients may determine the etiology in 53.3% of cases. Half of patients had thyroid dysgenesis. Arq Bras Endocrinol Metab. 2012;56(9):627-32.

Hipotiroidismo congénito: un diagnóstico que no debemos olvidar / Congenital hypothyroidism: a diagnosis not to forget

Summary: Congenital hypothyroidism (CH) is the most common cause of preventable mental retardation. Since 1994, Chile has a national plan for mass screening all newborns to diagnose the disease. Currently, the CH incidence is approximately 1:3163 newborn (NB). Approximately, 10 percent of these cannot be identified by screening programs, so the clinical suspicion is fundamental in the diagnosis. The most frequently clinical features observed in neonates or young infants are the presence of a posterior fontanelle greater than 5 mm, umbilical hernia and dry skin. It is important to determine the etiology of CH, but the etiological study should not delay the start of treatment. Early treatment determines a better prognosis of neurological development. A review of the CH screening program, pathophysiology, clinical presentation, and aspects of the study and treatment are presented in this study.

El hipotiroidismo congénito (HTC) es la causa más frecuente de discapacidad intelectual prevenible. Desde el año 1994 existe en Chile un plan nacional de tamizaje masivo a todos los recién nacidos para el diagnóstico de la enfermedad. Actualmente, la incidencia de HTC es de aproximadamente 1:3 163 recién nacidos (RN). Hasta un 10 por ciento de éstos puede no ser identificado por los programas de tamizaje, por lo que es importante la sospecha clínica del diagnóstico. Las características clínicas más frecuentemente observadas en RN o lactantes pequeños son la presencia de una fontanela posterior mayor de 5 mm, hernia umbilical y piel seca. Es importante determinar la etiología del HTC, pero el estudio etiológico no debe retrasar el inicio del tratamiento. El inicio precoz de éste determina un mejor pronóstico de desarrollo neurológico. Se presenta una revisión del programa de tamizaje de HTC, su fisiopatología, presentación clínica, y aspectos del estudio y tratamiento.

Incidence of congenital hypothyroidism in the city of Uberaba/Minas Gerais and etiological evaluation of the affected subjects / Incidência do hipotireoidismo congênito no município de Uberaba/Minas Gerais e avaliação etiológica dos afetados

OBJECTIVE: The objective of this study was to determine the incidence and etiology of congenital hypothyroidism (CH) in Uberaba, MG. SUBJECTS AND METHODS: From 2001 to 2010, by reviewing patient files from a public reference outpatient unit. The screening program covered 88% of live-born children. RESULTS: CH was diagnosed in 16 children, representing an incidence of 1:2,017 live-born children screened. The etiological evaluation was done in 15 children and revealed seven cases of thyroid dysgenesis, seven of dyshormonogenesis, and one case of transient hypothyroidism. One child moved away from the state before etiological investigation was carried out. CONCLUSION: We concluded that both the incidence of CH and of dyshormonogenesis as the main causes of CH were increased in the investigated region, but molecular studies are necessary for a better definition of etiology.

OBJETIVO: O objetivo deste estudo foi determinar a incidência e etiologia do hipotireoidismo congênito (HC) em Uberaba, MG. PACIENTES E MÉTODOS: Mediante revisão dos prontuários de pacientes atendidos no ambulatório de referência do serviço público, no período de 2001 a 2010. RESULTADOS: A cobertura do programa foi de 88%, sendo diagnosticadas 16 crianças com HC, com incidência de 1:2.017 nascidos vivos investigados. A avaliação etiológica foi realizada em 15 crianças, sendo diagnosticados sete casos de disgenesia tireoidiana, sete casos de disormonogênese e um caso de hipotireoidismo transitório. Uma criança não foi investigada devido à mudança de residência para outro estado. CONCLUSÕES: Concluímos que a incidência do HC é maior nesta região, assim como a disormonogênese como principal causa, sendo necessários estudos moleculares para melhor definição etiológica.

Absence of mutations in PAX8, NKX2.5, and TSH receptor genes in patients with thyroid dysgenesis / Ausência de mutações nos genes PAX-8, NKX2.5 e receptor de TSH em pacientes com disgenesia tireoidiana

OBJECTIVES: To precisely classify the various forms of TD, and then to screen for mutations in transcription factor genes active in thyroid development. SUBJECTS AND METHODS: Patients underwent ultrasound, thyroid scan, and serum thyroglobulin measurement to accurately diagnose the form of TD. DNA was extracted from peripheral leukocytes. The PAX8, and NKX2.5 genes were evaluated in all patients, and TSH receptor (TSHR) gene in those with hypoplasia. RESULTS: In 27 nonconsanguineous patients with TD, 13 were diagnosed with ectopia, 11 with hypoplasia, and 3 with athyreosis. No mutations were detected in any of the genes studied. CONCLUSION: Sporadic cases of TD are likely to be caused by epigenetic factors, rather than mutations in thyroid transcription factors or genes involved in thyroid development.

OBJETIVOS: Classificar corretamente as várias formas de DT e depois rastrear por mutações em genes que participam no desenvolvimento da tireoide. SUJEITOS E MÉTODOS: Os pacientes realizaram ultrassonografia, cintilografia e tireoglobulina sérica para o diagnóstico preciso de DT. DNA foi extraído de leucócitos periféricos. Os genes PAX8 e NKX2.5 foram estudados em todos os pacientes e o gene do receptor do TSH (TSHR) foi estudado na hipoplasia. RESULTADOS: Avaliaram-se 27 pacientes sem consanguinidade com DT, dos quais 13 foram diagnosticados com ectopia, 11 com hipoplasia e 3 com atireose. Nenhuma mutação foi detectada nos genes estudados. CONCLUSÃO: Casos esporádicos de DT são provavelmente causados mais por fatores epigenéticos do que por mutações em fatores de transcrição ou genes envolvidos no desenvolvimento tireoidiano.

Lóbulo piramidal de la glándula tiroides: imágenes en tomografía computarizada / Computed tomography imaging of the pyramidal lobe of the thyroid gland

El lóbulo piramidal de la glándula tiroides es una variante anatómica normal que se presenta con alta frecuencia en la población general. Dicha estructura está compuesta por tejido tiroideo normal, se ubica en la parte superior del istmo tiroideo y se dirige hacia arriba, continuándose con una cinta fibrosa que asciende hasta el agujero ciego en la base de la lengua. En este artículo se revisa de manera breve la anatomía y embriología de la glándula tiroides, para luego hacer una breve exposición acerca de los principales datos anatómicos, epidemiológicos e imágenes de tomografía computarizada del lóbulo piramidal de la glándula tiroides.

Mutations in the gene encoding paired box domain (PAX8) are not a frequent cause of congenital hypothyroidism (CH) in Iranian patients with thyroid dysgenesis / As mutações no gene PAX8 não constituem uma causa frequente de hipotireoidismo congênito em pacientes iranianos com disgenesia tiroidiana

OBJECTIVE: Congenital hypothyroidism (CH) may be caused by defects in the thyroid or in one of the stages in the synthesis of thyroid hormones. Thyroid dysgenesis may be associated with mutation in the paired box transcription factor 8 (PAX8) gene. We attempted to screen PAX8 gene mutation in 50 CH patients with thyroid dysgenesis. SUBJECTS AND METHODS: The patients were classified in two groups as agenesis and ectopic based on biochemical and para clinical tests. By employing PCR, Single Strand Conformation Polymorphism (SSCP) and sequencing, exons 3 to 12 of PAX8 gene with their exon-intron boundaries were studied. RESULTS: No mutation was found in these patients in any of the exons. CONCLUSION: Our results, once again, indicate that the PAX8 mutation rate is very low and can only explain a minority of the cases. Therefore, it is highly needed to further investigate the genes controlling development and function of thyroid.

OBJETIVO: O hipotireoidismo congênito (HC) pode ser causado por defeitos na formação da tireoide ou em uma das etapas da síntese dos hormônios tireoidianos. A disgenesia da tireoide pode ser associada a mutações no fator de transcrição PAX8. Neste estudo, foram rastreadas mutações no gene PAX8 em 50 pacientes com CH com disgenesia da tireoide. SUJEITOS E MÉTODOS: Os pacientes foram classificados em dois grupos, com agenesia ou com ectopia, segundo os testes bioquímicos e paraclínicos. Foram empregadas as técnicas de SSCP (Single Strand Conformation Polymorphism) e sequenciamento para analisar os éxons 3 a 12 do gene PAX8 e suas bordas éxon-intron. RESULTADOS: Nenhuma mutação foi encontrada nesses pacientes, em qualquer um dos éxons. CONCLUSÃO: Nossos resultados, mais uma vez, indicam que a taxa de mutação PAX8 é muito baixa e só pode explicar a minoria dos casos. Portanto, é altamente necessário investigar outros genes que controlam o desenvolvimento e as funções tireoideanas.