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)

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.

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

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.

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.