Preoperative and Postoperative Risk Stratification of Thyroid Papillary Microcarcinoma: A Comparative Study Between Kuma Criteria and 2015 American Thyroid Association Guidelines Risk Stratification.

Background: The incidence of micropapillary thyroid carcinoma (mPTC) has increased in the last decade. Active surveillance (AS) has been proposed as an alternative management for low-risk mPTC based on preoperative Kuma criteria. Controversy still exists on how to appropriately manage this group of patients, as some low-risk mPTC may harbor some postoperative features associated with disease recurrence as described in the 2015 American Thyroid Association (ATA) guidelines. Methods: We retrospectively reviewed 108 patients with histopathologic diagnosis of mPTC after surgery at a third level hospital in Mexico City from 2000 to 2018. Demographic and clinicopathologic data were analyzed as predictors for disease recurrence and/or metastatic disease (lymph node or distant). Comparison between group stratification based on preoperative Kuma criteria and postoperative 2015 ATA guidelines risk criteria for disease recurrence was performed. Measures of diagnostic accuracy were obtained for preoperative risk features according to the Kuma criteria. Results: Of 108 patients, 79 (73%) were classified as preoperative high-risk mPTC and 29 (27%) as low risk based on the Kuma criteria. Of these 79 high-risk patients, 38 (48%) were reclassified as low risk for disease recurrence, 12 (15%) as intermediate risk, and 29 (37%) remained as high risk based on the 2015 ATA risk criteria. Of the 29 preoperative low-risk patients, 19 (65.5%) remained as postoperative low risk for disease recurrence, 2 (7%) as intermediate risk, and 8 (27.5%) as high risk. Higher accuracy of preoperative risk features was obtained for lymph node and distant metastases, 84.2% and 97.2%, respectively. After multivariate analysis, age <40 years and microscopic extrathyroidal extension (ETE) were associated with higher risk for metastatic disease (lymph node or distant) in our cohort. Conclusions: Patients with mPTC under 40 years old and microscopic ETE are more prone to develop metastatic disease (lymph node or distant). One-third of our patients stratified as low-risk mPTC according to the Kuma criteria for AS had histopathologic features associated with a more aggressive clinical behavior or structural recurrence. In addition, lymph node and distant metastases are the preoperative risk features with the highest diagnostic accuracy for preoperative risk stratification.

Recurrent Papillary Thyroid Carcinoma to the Cervical Lymph Nodes: Outcomes of Compartment-Oriented Lymph Node Resection.

INTRODUCTION: Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications. PATIENTS AND METHODS: All patients who underwent LND for recurrent papillary thyroid carcinoma between 2000 and 2015 were included. Demography, the extent of the initial surgery, usage of 131I, the pattern of recurrence, diagnosis, details of the surgical reintervention, histological findings, surgical morbidity, and clinical and biochemical outcomes were analyzed. RESULTS: There were 11 (12.7%) males and 75 (87.2%) females with a mean age of 42.8 ± 14.6 years. Seventy-seven patients had undergone total thyroidectomy and in 67 (77.9%) some type of LN resection. In 76 (88.3%), 131I was administered after the initial surgery. We localized suspicious lymph nodes by US in all patients, and metastases were documented before surgery by FNA in 63. Seven (8.13%) patients underwent central LND, 63 (73.2%) lateral LND and 16 (18.6%) both, central and lateral LND. Major complications occurred in 6 patients (6.9%). Sixty-two (72.0%) patients received 131I after surgery. A second surgical re-exploration was performed in 30 (34.8%) patients, and 7 patients required 3 or more additional LND. In a mean follow-up of 59.4 ± 39 months, 51 (59.3%) patients are clinically, radiologically and biochemically free of disease. CONCLUSIONS: In this series, compartment-oriented lymph node resection of recurrent papillary thyroid carcinoma leads to a final clinical and biochemical disease-free status of 59.3% with 6.9% of major complications.

Deletion of exon 1 of the SLC16A2 gene: a common occurrence in patients with Allan-Herndon-Dudley syndrome.

BACKGROUND: Allan-Herndon-Dudley syndrome (AHDS) is an X-linked type of mental retardation resulting from hindered thyroid hormone access to neurons. Clustered nonrecurrent deletions of SLC16A2 exon 1 have been described in three patients with AHDS. We report a fourth patient with such a deletion and discuss possible mechanisms leading to these rearrangements. CASE PRESENTATION: A three-and-a-half-year-old male with clinical and biochemical AHDS phenotype and a history of normal neonatal screening for hypothyroidism underwent SLC16A2 molecular analysis. Unexpectedly, he showed skeletal signs of hypothyroidism. METHODS AND RESULTS: The exons of the SLC16A2 (MCT8) gene and the sequences surrounding exon 1 were amplified using PCR. The patient had a 36-kb deletion affecting exon 1 of SLC16A2. The deletion junction was subjected to bioinformatic analyses, along with two other reported exon 1 deletion junctions, identifying possible sequence features and mechanisms responsible for such genomic rearrangements. DISCUSSION/CONCLUSION: This patient had a classic AHDS phenotype with an unexpectedly large anterior fontanel and delayed bone age and dentition. Bioinformatic analyses suggested that exon 1 deletions in patients with AHDS are caused by microhomology-mediated replicative-based and nonhomologous end-joining mechanisms. Rearrangement susceptibility may be due to the size of intron 1 and the percentage of repeat sequences.

[Thyroid hormone resistance (THR): a case report]. / Resistencia a hormonas tiroideas (RTH). Reporte de caso.

Thyroid hormone resistance is a syndrome characterized by a reduced response to thyroid hormone with different degrees of resistance at target tissues. We present the clinical features, physical findings, and study protocol in a woman with thyroid hormone resistance. An arginine to tryptophan mutation on the ß isoform of the thyroid hormone receptor gene was demonstrated. Thyroid hormone resistance is an uncommon cause of thyroid dysfunction. It is necessary to perform an adequate study and confirmation to avoid an inadequate and ineffective treatment of this condition.

[Subclinical thyroid dysfunction. Diagnostic and therapeutic considerations]. / Disfunción tiroidea subclínica. Consideraciones diagnósticas y terapéuticas.

Mild thyroid dysfunction is a biochemical diagnosis classified either as subclinical hypo or hyperthyroidism. It can occur in young patients with a frequency that increases with age, presenting higher morbidity and mortality then. To suspect the diagnosis, it is important to keep in mind some of the nonspecific signs and symptoms of the disease, and the possible laboratory abnormalities. Furthermore, it is advisable to establish an appropriate range of values for thyrotropin (TSH), determine the presence of high risk factors in individuals under evaluation, and the possible consequences on their well-being. Taking into consideration that a non-excessive, adequate hormonal substitution prevents, improves or resolves the harmful effect on different systems of the organism; as well as an early and opportune detection and treatment of mild or subclinical thyroid dysfunction could be beneficial for the general population.

[Low galectin-3 capacity to discriminate thyroid lesions]. / Baja capacidad de galectina-3 para discriminar lesiones tiroideas.

UNLABELLED: Galectin-3 is considered useful in identifying lesions included in the term follicular tumour. OBJECTIVE: To evaluate galectin-3's power to discriminate among diverse thyroid lesions and to identify a set point of expression at which there is the least possible false positive results. METHODS: 26 follicular carcinomas and 104 assorted thyroid lesions were analysed (8 Hashimoto's thyroiditis, 18 goiter, 44 adenoma, 27 papillary carcinoma and 7 normal glands). Immunohistochemistry for galectin-3 was performed way (NCL-GAL-3, 1:100, Novocastra, UK). In a blinded manner intensity and percentage of expression were evaluated, as was its capacity to identify the previously mentioned thyroid entities with 2 x 2 tables. Minimum reactivity set point values were identified and the one which presented the least false positive cases was selected. RESULTS: A reaction was considered positive when 25% of the cells were marked, in which case neither the Hashimoto's thyroiditis, goiter, nor the residual tissue were positive for galectin-3. A positive galectin-3 reaction was identified in 4/44 adenomas, 5/26 follicular carcinomas and 18/27 papillary carcinomas. From a total of 53 carcinomas, 23 showed positive and 30 a negative reaction to galectin-3. Thus, galectin-3's sensitivity to discriminate between benign and malignant lesions was 94% while its specificity was 43%. When comparing follicular carcinoma with adenoma, sensibility was 19% while specificity was 91%. The positive predictive value was 56% and the negative predictive value 66%. Galectin-3 was most useful for identifying papillary thyroid carcinoma. CONCLUSIONS: Galectin-3 has limited value to distinguish benign from malignant thyroid lesions. The reaction must be considered positive when at least 25% of cells are marked.

Comportamiento clínico de adenomas foliculares mayores de 5 cm / Clinical course of follicular adenomas greater than 5 cm

Introducción. Se ha sugerido que el tamaño de los tumores foliculares y su tiempo de evolución podrían ser de utilidad para predecir el diagnóstico de malignidad. Objetivo. El objetivo del presente estudio fue evaluar el comportamiento clínico de 35 ade4nomas foliculares = 5 cm tratados mediante cirugía para enfermedad benigna en un periodo de 23 años. Sede. Instituto Nacional de la Nutrición. México. Pacientes y métodos. Del total de pacientes llevados a cirugía por enfermedad benigna, en nuestro hospital, se seleccionaron aquellos con tumores iguales o superiores a 5 cm. Se revisaron sus características general, estudio histológico y su evolución a largo plazo en busca de recidiva o metástasis. Se empleo prueba t de Student para el análisis estadístico. Resultados. Se encontraron 30 mujres y 5 hombres con una edad promedio de 41.6 ñ 14.3 años. Treinta y dos tumores fueron sólidos y 3 mostraron un patrón mixto. El diámetro promedio de las lesiones fue de 6.8 ñ 1.4 cm. Se realizó lobectomía unilateral en 27 pacientes y tiroidectomía subtotal en 8. Se estableció el diagnóstico de adenoma folicular en todos los pacientes, revisando en promedio 6 ñ 3 laminillas. En un seguimiento promedio de 15.3 ñ 7.04 años, no hubo evidencia de recurrencia local o metástasis a distancia en ninguno de los pacientes. Se comparó el tiempo de evolución de los pacientes con el de un grupo de 25 enfermos con carcinoma folicular sin encontrar diferencias significativas. Conclusión. Ni el tamaño del tumor ni su tiempo de evolución son marcadores útiles para predecir malignidad

Carcinoma anaplásico de tiroides en el Instituto Nacional de la Nutrición Salvador Zubirán / Anaplastic carcinoma of the Thyroid at the Instituto Nacional de la Nutricion Salvador Zubiran

Antecedentes. El carcinoma anaplástico de tiroides (CAT) es un tumor muy agresivo cuya supervivencia media después del diagnóstico es de seis meses. Su rareza ha limitado el conocimiento de muchas de sus características clínicas y de evolución. Objetivo. Analizar la forma de presentación, diagnóstico, tratamiento y superviviencia de los pacientes con CAT, así como sus características morfológicas, inmunohistoquímicas y contenido nuclear de DNA. Pacientes y métodos. Fueron 12 pacientes con CAT (11 mujeres) con edad promedio de 65 años y que recibieron atención en nuestra institución de 1970 a 1995. La información clínica se obtuvo de los expedientes y para los análisis morfológico, inmunohistoquímico y genético se emplearon laminillas provenientes de bloques de tejido archivado. Resultados. En 10 pacientes se documentó coexistencia de enfermedad tiroidea (9 bocios y un Graves). La presentación más frecuente fue una tumoración de crecimiento rápido acompañada de disfagia, dolor cervical, disfonía y disnea que en 10 correspondió gamagráficamente a un nódulo frío. En todos se corroboró el diagnóstico por biopsia o por histología. El patrón celular predominante fue fusiforme. Se encontró coexistencia con carcinoma papilar en ocho pacientes. En seis casos estudiados, se demostró positividad para S-100 y vimentina en todos, en 5 (83 por ciento) se detectó el antígeno de membrana epitelial, el antígeno carcinoembrionario en la mitad, para tiroglobulina y calcitonina en 2/6 casos, y para enolasa neuronal específica en 1/6. La citometría de flujo mostró un patrón diploide de DNA en los 6 casos evaluados. Se logró resección completa en 2/11 sometidos a cirugía. Conclusiones. El CAT es un tumor agresivo que se asocia con otras enfermedades tiroideas. El patrón morfológico predominante es el fusiforme, con frecuente reactividad para vimentina, S-100 y antígeno de membrana epitelial, y un patrón diploide de DNA

Tratamiento quirúrgico de bocio multinodular en el Instituto Nacional de la Nutrición Salvador Zubirán / Surgical treatment of multinodular goiter at the Instituto Nacional de la Nutricion Salvador Zubiran

Antecedentes. La resección quirúrgica es la primera opción en el manejo de las lesiones obstructivas o con sospecha de malignidad en el bocio multinodular (BMN). La magnitud de la resección y la necesidad de supresión hormonal postoperatoria son aún aspectos de debate. Objetivo. Analizar los resultados terapéuticos de 101 pacientes intervenidos quirúrgicamente por BMN entre 1980 y 1995. Material y métodos. Se revisaron los expedientes clínicos de los pacientes con énfasis en la indicación quirúrgica, tipo de resección, diagnóstico definitivo, complicaciones y evolución. El seguimiento promedio fue de tres años (0.5-12). Resultados. Diez pacientes fueron varones y 91 mujeres, con edad promedio de 46 años. En 60 pacientes la cirugía se indicó por sospecha de malignidad, en 33 por obstrucción y en 8 por razones cosméticas. Se efectuaron 30 lobectomías, 55 tiroidectomías subtotales bilaterales y 16 totales; 83 pacientes recibieron, además, tratamiento hormonal postoperatoria. El diagnóstico definitivo fue de bocio multinodular en 89 pacientes y cáncer en 12. En el grupo con enfermedad benigna hubieron tres recurrencias asintomáticas (con hemitiroidectomía y tratamiento hormonal supresivo). Conclusión. La tiroidectomía subtotal mostró ser el mejor procedimiento para el manejo del BMN ya que en nuestro estudio no se acompañó de recurrencia y su frecuencia de complicaciones fue del 2 por ciento