Cirugía profiláctica en cáncer medular de tiroides hereditario / Prophylactic surgery in hereditary medullary thyroid cancer

Introducción: Se estima que del total de los cánceres, el 5-10% tendría una base genética. Actualmente es posible identificar a los individuos con predisposición genética en algunos cánceres como manera de intervenir precozmente en el desarrollo de esta enfermedad. Objetivos: Evaluar la utilidad de la cirugía profiláctica en el cáncer medular de tiroides hereditario. Material y métodos: Este trabajo es una revisión de literatura de diferentes estudios extraídos de bibliotecas electrónicas como Scientific Electronic Library Online (SciELO), MedLine-PubMed y UpToDate, mediante la construcción de preguntas clínicas y términos MeSH enfocados principalmente en la búsqueda específica de información sobre el cáncer medular de tiroides hereditario. Resultados: Los estudios revisados demuestran que la tiroidectomía profiláctica con resección linfática cervical representa el único tratamiento eficaz en el caso del cáncer medular de tiroides hereditario. Conclusiones: La cirugía profiláctica ha demostrado una importante disminución del riesgo de cáncer de tiroides y se considera una conducta de rigor en portadores del gen RET en el cáncer medular de tiroides.

Introduction: Approximately 5-10% of global cancer has a genetic base. Nowadays it is possible to identify those who have a genetic predisposition for some cancers, so they can be treated in short term. Objectives: Evaluate how useful is prophylactic surgery on hereditary Medullary Thyroid Cancer. Materials and methods: This investigation is a literature review of different research papers from electronic databases such as Scientific Electronic Library Online (SciELO), MedLine-PubMed and UpToDate. The research was made with clinical queries and MeSH terms, specially focused on hereditary Medullary Thyroid Cancer. Results: This research shows that prophylactic Thyroidectomy with cervical lymph node resection is the only effective and curative treatment for hereditary Medullary Thyroid Cancer. Conclusions: Prophylactic surgery has proof an important role decreasing the risk on Hereditary Thyroid cancer Syndrome and in RET carriers surgery is considered a must.

Cáncer medular de tiroides: Experiencia quirúrgica en 10 años / Medullary thyroid cancer: Review of 28 patients

Background: Medullary thyroid cancer (MTC) represents approximately 5% of all thyroid cancers. Surgery is the only curative treatment, which includes total thyroidectomy and in most cases, neck dissection. Aim: To report our 10-year experience with surgical treatment of MTC. Material and Methods: Review of medical records and pathology reports of a university hospital. We retrieved data from 28 patients aged 47.2 ± 16 years (21 women) operated for a MTC treated between June 2002 and June 2012. Results: In 20 patients, MTC was diagnosed in the preoperative period. Total thyroidectomy was performed in all cases and included a neck dissection in 24 patients. Median follow-up was 48 (2-120) months. Twenty-five patients (89.2%) achieved complete remission of the disease and three had disease recurrence. There were no deaths during the follow up. Conclusions: The diagnosis of MTC is mainly based on cytology. Total thyroidectomy with neck dissection is the treatment of choice. An early-stage diagnosis is associated with low rates of recurrence and absence of mortality.

Surgical approach to medullary thyroid carcinoma associated with multiple endocrine neoplasia type 2

We briefly review the surgical approaches to medullary thyroid carcinoma associated with multiple endocrine neoplasia type 2 (medullary thyroid carcinoma/multiple endocrine neoplasia type 2). The recommended surgical approaches are usually based on the age of the affected carrier/patient, tumor staging and the specific rearranged during transfection codon mutation. We have focused mainly on young children with no apparent disease who are carrying a germline rearranged during transfection mutation. Successful management of medullary thyroid carcinoma in these cases depends on early diagnosis and treatment. Total thyroidectomy should be performed before 6 months of age in infants carrying the rearranged during transfection 918 codon mutation, by the age of 3 years in rearranged during transfection 634 mutation carriers, at 5 years of age in carriers with level 3 risk rearranged during transfection mutations, and by the age of 10 years in level 4 risk rearranged during transfection mutations. Patients with thyroid tumor >5 mm detected by ultrasound, and basal calcitonin levels >40 pg/ml, frequently have cervical and upper mediastinal lymph node metastasis. In the latter patients, total thyroidectomy should be complemented by extensive lymph node dissection. Also, we briefly review our data from a large familial medullary thyroid carcinoma genealogy harboring a germline rearranged during transfection Cys620Arg mutation. All 14 screened carriers of the rearranged during transfection Cys620Arg mutation who underwent total thyroidectomy before the age of 12 years presented persistently undetectable serum levels of calcitonin (<2 pg/ml) during the follow-up period of 2-6 years. Although it is recommended that preventive total thyroidectomy in rearranged during transfection codon 620 mutation carriers is performed before the age of 5 years, in this particular family the surgical intervention performed before the age of 12 years led to an apparent biochemical cure.

Cáncer medular de tiroides esporádico de curso agresivo, en un adolescente varón / Madullary thyroid cancer in a 14 years old male: case report

Medullary thyroid cancer can appear sporadically or as part of a multiple endocrine neoplasia type 2A or 2B. In both conditions, it is associated with mutations of proto oncogene RET (rearranged during transfection). We report a 14 years old male presenting with a bone lesion in the skull followed by a hard cevical mass. A CAT scan showed an invasive thyroid nodule with involvement of regional lymph nodes , osteolytic lesions in skull, spine and ribs and liver metastases. Serum calcitonin was markedly elevated (9752 pg/ml, normal below 14 pg/ml). Fine needle biopsy showed a medullary thyroid carcinoma and the patient was subjected to a total thyroidectomy and radical cervical dissection. In the postoperative period the patient required calcium and vitamin D supplementation. Serum calcitonin 15 days after surgery was 11.692 pg/ml. Palliative radiotherapy was indicated for spine pain. A percutaneous gastrostomy was indication for nutritional support. The molecular study did not detect mutations of RET gene between exons 10 and 16.

Carcinoma medular de tiroides: experiencia de 20 años / Medullary thyroid carcinoma: 20 years experience

Background: Medullary thyroid carcinoma (MTC) is a rare malignant tumor that arise from C cells. Surgical treatment and its results are controversial, so we decided to study it. Aim: To describe clinically MTC, treatment and outcomes in the long term. Material and Method: We retrospectively reviewed medical records of patients with MTC operated in our hospital between the years 1987 and 2007. We analyzed the cli-nical characteristics, treatment, morbidity and long-term follow up. Results: There were 24 patients operated with a mean age of 46.1 +/- 16.6 years. The main form of presentation was painless increased cervical volume (56.2 percent). In 15 percent this pathology was part of a MEN 2b. All of them have had a total thyroidectomy, which was extended in 50 percent of cases. The 35.2 percent were multifocal, 29.4 percent bilateral and 62.5 percent had metastatic lymph node involvement. Five patients remained higher calcitonin levéis in the postoperative period and 9 patients recurred clinically on average 4.5 years after surgery. The presence of persistent disease was significantly associated with hereditary MTC (p = 0.0088) and the clinical recurrence was significantly determined by the presence of not expanded total thyroidectomy (p = 0.0196). The probability of surviving more than 19 years was 66.6 percent (95 percent CI = 0.24 to 0.89). Conclusions: The MTC is a rare tumour and treatment of choice is surgery. The persistent disease is associated with hereditary MTC form, and the clinical recurrence is associated with not expanded total thyroidectomy. We recommend total thyroidectomy with central voiding and radical modified jugular dissection.

Antecedentes: El carcinoma medular de tiroides (CMT) es un tumor maligno poco frecuente, originado a partir de las células C. Su tratamiento quirúrgico y resultados son controvertidos, por lo que hemos decidido estudiarlo. Objetivo: Describir clínicamente el CMT, tratamiento y resultados a largo plazo. Material y método: Se revisaron retrospectivamente las fichas clínicas de pacientes con CMT operados en nuestro hospital entre 1987 y el 2007. Se analizaron las características clínicas, tratamiento, morbilidad y seguimiento a largo plazo. Resultados: Se operaron 24 pacientes, cuya edad media fue 46,1 +/- 16,6 años. La principal forma de presentación fue aumento de volumen cervical (56,2 por ciento). Un 15 por ciento formaba parte de una NEM 2b. A todos se les realizó una tiroidectomía total, ampliada en el 50 por ciento de los casos. El 35,2 por ciento eran multifocales, el 29,4 por ciento bilaterales y el 62,5 por ciento tenía metástasis ganglionar. Cinco pacientes mantuvieron niveles de calcitonina elevados en el postoperatorio y nueve pacientes recurrieron clínicamente, en promedio, a los 4,5 años. La enfermedad persistente se asoció significativamente con CMT hereditario (p = 0,0088) y la recurrencia clínica a tiroidectomía total no ampliada (p = 0,0196). La probabilidad de sobrevivir más de 19 años fue 66,6 por ciento (IC 95 por ciento = 0,24 a 0,89). Conclusiones: EL CMT es un tumor raro cuyo tratamiento de elección es la cirugía. La persistencia de enfermedad se asocia con la forma hereditaria, y la recurrencia clínica con la tiroidectomía total no ampliada, lo que nos hace recomendar una tiroidectomía total asociada a vaciamiento central y disección yugular radical modificada.

Cáncer de tiroides pediátrico: serie de casos / Retrospective review of pediatric patients with thyroid cancer

Background: In childhood, thyroid cancer is uncommon and has a different biological behaviour than in adults. Aim: To analyze the surgical experience in thyroid cancer in children. Material and Methods: Review of medical records of patients aged 15 years or less with a thyroid cancer, operated in a Regional hospital between 1980 and 2007. Results: Six females and 2 males, aged 9 to 15 years, were operated in the study period. Five had a family history of thyroid diseases. Four had involvement of cervical lymph nodes at the moment of operation but none had systemic dissemination. All were euthyroid. A total thyroidectomy was performed in four patients. Cervical lymph node dissection was also performed in four patients. No immediate complications were recorded. One patient had a local relapse. Five patients were also treated with radioiodine. At the end of the follow up ranging from 108 to 320 months, all patients are asymptomatic. The pathological study disclosed a papillary carcinoma in seven and medullary carcinoma in one patient. Conclusions: Thyroid cancer in childhood has low mortality rates and surgical treatment is safe and effective.

El cáncer de tiroides en edad pediátrica es extremadamente infrecuente y tiene un comportamiento biológico diferente al adulto. El objetivo de este estudio es analizar la experiencia quirúrgica local en los últimos 27 años. Estudio de serie de casos describiendo las características anatomoclínicas, quirúrgicas, resultados del tratamiento y condición actual de los pacientes analizados mediante estadística descriptiva, realizando curva de sobrevida con método de Kaplan-Meier. Se intervinieron quirúrgicamente 8 pacientes por cáncer tiroideo, 6 del sexo femenino y 2 del masculino, con edad promedio de 13 años (9 a 15 años). Cinco tenían antecedentes familiares de patología tiroidea. Cuatro presentaron al momento del diagnóstico linfoadenopatías metastáticas cervicales, ninguno evidenció diseminación sistémica. Todos presentaban estado eutiroideo. El diagnóstico histopatológico concluyó carcinoma papilar en 7 casos y medular en 1. Se realizó tiroidectomía total en 4 pacientes. En 4 se practicó linfadenectomía cervical. No hubo complicaciones postoperatorias inmediatas. En 5 se complementó con radioyodoterapia. Una paciente desarrolló recidiva regional. Al término del estudio 7 llevan vida normal. Una paciente con carcinoma medular esporádico falleció siete años después de la cirugía, a causa de metástasis pulmonares y hepáticas. El seguimiento promedio de los cánceres papilares fue de 165 meses (108 a 320 meses). El cáncer de tiroides en edad pediátrica se asocia a una supervivencia prolongada, incluso en etapas avanzadas. La extensión de cirugía en los carcinomas papilares debe considerar factores pronósticos como tamaño y extensión del tumor primario, presencia o ausencia de metástasis y ciertamente, experiencia y buen juicio del equipo quirúrgico.

Prognostic influence of clinical and pathological factors in medullary thyroid carcinoma: a study of 53 cases

OBJECTIVES AND INTRODUCTION: Medullary thyroid carcinoma, a neoplasia of intermediate prognosis and differentiation, does not always respond predictably to known treatments. This study aimed to correlate the clinical progression of surgically treated patients with clinical and pathological data. METHODS: A total of 53 patients were followed for 75 months (mean average) in tertiary-care hospital. The clinical status of patients at the end of the study period was characterized to determine correlations with a range of disease aspects. A value of p < 0.05 was considered statistically significant. RESULTS: Twenty-two patients (41.5 percent) were alive and disease-free at the end of the follow-up period; twenty-three patients (43.4 percent) had persistent disease; and eight patients (15.1 percent) had recurrent disease. Four patients (7.6 percent) died from medullary thyroid carcinoma with clinical and/or imaging evidence of neoplasia. The following aspects demonstrated statistically significant correlations with the final medical condition: positive initial cervical examination (p = 0.002); neoplastic extensions to the thyroid capsule (p = 0.004) and adjacent tissues (p = 0.034); cervical lymph node metastases (p < 0.001); diameter of neoplasia (p = 0.018); TNM (tumor, node and metastasis) Stage (p = 0.001) and evidence of distant and/or cervical diseases in the absence of a cure (p = 0.011). Through logistic regression, the presence of cervical lymph node metastases was considered an independent variable (p < 0.001). CONCLUSIONS: Clinical and pathological aspects of patients with surgically treated medullary thyroid carcinomas are predictors of disease progression. Specifically, even treated cervical lymph node metastases are significantly correlated with disease progression.

Hypercalcitoninemia is not pathognomonic of medullary thyroid carcinoma: [revision]

Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (> 2-4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (~90%-100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, < 5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma. In multiple endocrine neoplasia type 2 (MEN2), RET mutation analysis is the gold-standard for the recommendation of total preventivethyroidectomy to relatives at risk of harboring a germline RET mutation (50%). False-positive calcitonin results within MEN2 families have led to incorrect indications of preventive total thyroidectomy to RET mutation negative relatives. In this review, we focus on the differential diagnosis of hypercalcitoninemia, underlining its importance for the avoidance of misdiagnosis...

Neurofibroma de tireóide em uma paciente com neurofibromatose tipo 1 / Neurofibroma of thyroid in a patient with neurofibromatosis type 1

A neurofibromatose tipo 1 (NF1), também conhecida como doença de von Recklinghausen, é uma doença autossômica dominante com alto grau de variabilidade da expressão clínica, comumente envolvida na formação de tumorações na maioria das vezes de origem benigna, localizadas principalmente na região da cabeça e do pescoço, sendo a tireóide acometida raramente. Porém existe na literatura a associação com carcinoma medular da tireóide (CMT), necessitando sempre sua exclusão. Relatamos o caso de uma paciente com NF1, com um nódulo de tireóide não-funcionante e sintomas obstrutivos. Foi realizada ressecção cirúrgica da lesão, com achados histopatológicos compatíveis com neurofibroma em tecido tireoidiano. A importância desse caso deve-se não só à raridade dessa apresentação da NF1, mas também à possibilidade de associação desta com CMT, tumor agressivo com possibilidade de cura pela ressecção cirúrgica.

The neurofibromatosis type 1 (NF1), also known as von Recklinghausen’s disease, is an autosomal dominant disorder, with high degree of variability of clinical expression, usually involved with formation of tumors, with benign origin in the majority of cases mainly localized in the region of the head and neck and rarely incident in the thyroid area. However, the association with medullary carcinoma of the thyroid (MCT) exists in literature and needs to be excluded. We report a case of a patient with NF1, nonfunctional thyroid nodule and obstructive symptoms. Surgical resection of lesion was performed, with histopathologic findings compatible with neurofibroma in thyroid tissue. This case is relevant not only because of the rarity of the presentation of NF1, but also due to the likely association with MCT, an aggressive tumor that can be cured by surgery.

Carcinoma medular de tireóide: abordagem para prática clínica / Medullary thyroid carcinoma: na approach to clinical practice

O carcinoma medular da tireóide (CMT) representa 5 por cento dos tumores malignos dessa glândula e aproximadamente 25 por cento são hereditários, estes associados a mutações no proto-oncogene RET e ocasionalmente a outras neoplasias endócrinas (feocromocitona hiperparatireoidismo). O rastreamento familiar seguido da tireoidectomia naqueles com mutação no RET evita o aparecimento da doença em muitos indivíduos. O CMT esporático geralmente se apresenta como nódulo palpável ou já com sintomas de extensão extratireoidiana. Hipercalcitoninemia ocorre invariavelmente na doença clinicamente aparente. Recomenda-se tireoidectomia total com ressecção bilateral de lifonodos como tratamento inicial e, ocasionalmente, radioterapia, mas não (131) como terapia adjuvante. O seguimento é feito com as dosagens de CT e CEA, com realização de métodos de imagens nos pacientes com marcadores elevados. Presença de metástases linfonodais extensas e invasão extratireoidiana são fatores associados à menor chance de cura bioquímica (CT indetectável). Quando esta é alcançada, a sobrevida livre de doença em longo prazo é de 95 por cento.

Surgical approach to medullary thyroid cancer

Medullary thyroid cancer (MTC) compromises 3-5 percent of all thyroid cancers and arises from parafollicular or calcitonin-producing C cells. It may be sporadic (75 percent of cases), or may occur as a manifestation of either the hereditary syndrome Multiple Endocrine Neoplasia type 2 (MEN 2A or MEN 2B) (25 percent of cases), or rarely as an isolated familial syndrome (FMTC). Complete surgical resection comprising in most cases total thyroidectomy with central lymph node dissection at an early stage of the disease is the only potential cure for MTC. The familial form of the disease, MEN-2A occupies a unique place in surgical history, having been the first disease where surgical removal of an affected organ was undertaken before the development of malignancy, solely on the basis of genetic testing. Total thyroidectomy prior to the development of invasive cancer completely avoids an otherwise lethal malignancy. Timing of prophylactic surgery is based on models that utilise genotype-phenotype correlations, which have now been stratified into three risk groups based on the specific codon involved. MTC should be followed with postoperative serial serum calcitonin levels to survey for persistent or recurrent disease as indicated by detectable levels. The challenge however, if calcitonin levels are increased, is to find the source of its production. The first localisation technique recommended would be ultrasound of the neck, since there is a high frequency of local recurrence and cervical node metastasis, followed by a total body CT scan and bone scintigraphy.

O carcinoma medular de tiróide (CMT) abrange 3-5 por cento do câncer de tiróide em geral e surge da célula parafolicular ou célula C produtora de calcitonina. Pode ser esporádico (75 por cento dos casos), ou pode ocorrer como uma das manifestações das síndromes hereditárias Neoplasia Endócrina Múltipla tipo 2 (NEM2A ou NEM2B) (25 por cento dos casos), ou mais raramente como uma síndrome familiar isolada (CMTF). A ressecção cirúrgica completa, que na maioria dos casos consiste de tireoidectomia total com dissecção dos linfonodos nos estágios precoces da doença, é a única forma de cura potencial de CMT. A forma de doença familiar da patologia NEM2A ocupa um lugar único na história da cirurgia, tendo sido a primeira doença onde a remoção cirúrgica de um órgão afetado foi realizada antes do desenvolvimento da malignidade, baseado somente no teste genético. A tireoidectomia total antes do desenvolvimento do câncer invasivo evita de outra forma a malignidade letal. A época da cirurgia profilática está baseada nos modelos que utilizam a correlação genótipo-fenótipo, que atualmente está estratificada em três grupos de risco baseado no códon envolvido. O CMT deve ser acompanhado após a cirurgia com dosagem de calcitonina sérica, cujo nível, quando detectável, indicaria a persistência ou recorrência da doença. O desafio, no entanto, se os níveis de calcitonina estão elevados, é encontrar a fonte desta produção. A primeira técnica de localização recomendada seria o ultrassom do pescoço, já que ocorre uma alta freqüência de recorrência local e de metástase dos nódulos cervicais, seguida de tomografia computadorizada do corpo inteiro e de cintilografia óssea.

Carcinoma familiar del tiroides no medular (CFTNM): características de presentación en 17 casos / Clinical features of 17 patients with familial non medullary thyroid carcinoma

Background: Papillary thyroid carcinoma can have familial aggregation. Aim: To compare retrospectively familial non medullary thyroid carcinoma (FNMTC) with sporadic papillary thyroid carcinoma (PTC). Material and methods: Retrospective analysis of medical records of patients with thyroid carcinoma. An index case was defined as a subject with the diagnosis of differentiated thyroid carcinoma with one or more first degree relatives with the same type of cancer. Seventeen such patients were identified and were compared with 352 subjects with PTC. Results: The most common affected relatives were sisters. Patients with FNMTC were younger than those with PTC. No differences were observed in gender, single or multiple foci, thyroid capsule involvement, surgical border involvement, number of affected lymph nodes and coexistence of follicular hyperplasia. Patients with FNMTC had smaller tumors and had a nine times more common association with lymphocytic thyroiditis. Five patients with FNMTC had local recurrence during 4.8 years of follow up. Conclusions: Patients with FNMTC commonly have an associated chronic thyroiditis, are younger and have smaller tumors than patients with PTC.

Neoplasia endocrina múltiple atípica presentación de un caso / Atypical multiple endocrine neoplasia: a case presentation

Las neoplasias endocrinas múltiples constituyen síndromes con herencia autosómica dominante en los cuales hay afectación tumoral de 2 o más glándulas endocrinas, agrupadas según la afectación glandular en grupos: 1, 2A, 2B y las mixtas. Presentamos una paciente atendida en el INEN, del sexo femenino, de 44 años de edad, que a los 24 años fue operada de adenoma bronquial tipo carcinoide, 11 años más tarde fue intervenida quirúrgicamente por carcinoma medular del tiroides, y 7 años después comienza con aumento de volumen de las manos y los pies, por lo que ingresa en nuestro servicio donde se le diagnostica un adenoma hipofisario productor de GH, un tumor de la pineal, así como un tumor cromafín del riñón derecho. Dada la atipicidad del cuadro, y por no haber encontrado en la literatura revisada casos similares, consideramos oportuna su presentación(AU)

Multiple endocrine neoplasm are syndromes with autosomal dominant inheritance, where there is tumoral involvement of two or more endoce glands, grouped by glandular afection as: 1, 2A, 2B, and mixed. Case of a female patient, aged 44 seen in National Institute of Endocrinology (NIEN) and that when she aged 24 was operted on by a carcinoid bronchial adenoma, eleven year after she showed a increase in hands and feets volumen and is admissed in our service and is diagnosed as HG-producer hypophyseal adenoma, a tumor of pineal gland as well as a chromaffin tumor in right kidney. Due to atypical picture, and the lack of similar cases in reviewed literature, we considered appropriate its presentation(AU)

Impact of RET proto-oncogene analysis on the clinical management of multiple endocrine neoplasia type 2

A neoplasia endócrina múltipla tipo 2 (NEM2) é caracterizada pela ocorrência do carcinoma medular de tireóide (CMT), hiperparatiroidismo primário (HPT) e feocromocitoma (FEO).1-12 Desde 1993, quando as primeiras mutações do tipo missense no proto-oncogene RET (RET), associadas a NEM2 foram identificadas, 46 diferentes mutações causadoras de doenças foram descritas.13-17 Como há uma forte correlação genótipo-fenótipo na NEM2, a detecção de mutações no RET adquiriu grande impacto no tratamento precoce do CMT e NEM2. A NEM2 persiste como uma doença subdiagnosticada e/ou tardiamente diagnosticada em várias áreas geográficas do globo. A análise de mutações do RET deve ser realizada em todas os casos de NEM2 e atualmente, a tireoidectomia total profilática é indicada para todos os indivíduos portadores de mutações no RET.1 Para a grande maioria dos portadores de mutações gaméticas ativadoras no RET este procedimento cirúrgico é indicado nos primeiros anos de vida, promovendo melhora na qualidade de vida, aumento da sobrevida ou mesmo levando à cura definitiva.1 Discutimos nesta revisão, o impacto da análise do proto-oncogene RET na conduta clínica da neoplasia endócrina múltipla tipo 2. Além disso, o diagnóstico molecular do RET fornece à clínicos e cirurgiões a mais valiosa das informações, permitindo indicação de tireoidectomia total profilática.

Cáncer de tiroides en niños / Thyroid cancer in children

El cáncer de tiroides en la niñez es muy inusual, razón por la cual sus características clínicas son poco conocidas y su tratamiento suscita controversias. Presentamos 6 niños con cáncer de tiroides, 5 del tipo palpitar y 1 del tipo medular esporádico; 4 del sexo femenino y 2 del masculino, con edad promedio de 13 años (margen 9 a 15 años). Todos fueron tratados quirúrgicamente y la extensión de la cirugía varió según el tipo histológico y el estadio de la enfermedad. No hubo complicaciones postoperatorias inmediatas. Una paciente con cáncer papilar evolucionó con recidiva regional ipsilateral en 2 oportunidades y la niña con cáncer medular falleció por diseminación a los 84 meses de realizada la cirugía. El seguimiento promedio de los cánceres papilares es de 119 meses (margen 62 a 175 meses). Al cierre de esta revisión los 5 niños vivos se encuentran sin evidencias de enfermedad

Abordagem clínica e laboratorial do bócio uninodular sólido: vantagens da determinaçäo da calcitonina sérica por métodos distintos no rastreamento do carcinoma medular de tireóide, forma esporádica / Clinical and laboratorial approach of solid uninodular goiter: advantage of serum calcitonin determination by different methods in medullar thyroid carcinoma screening, sporadic form

A apresentação clínica mais freqüente da forma esporádica do carcinoma medular da tireóide (CMT) é o bócio uninodular sólido (BUS), apresentação esta semelhante aos demais tumores que afetam a glândula. O estabelecimento da freqüência de CMT em BUS apresenta implicações importantes não só diagnósticas, como também terapêuticas, visto a abordagem cirúrgica do CMT diferir de outros tumores tireoideanos. Para investigar a prevalência de CMT em BUS, dosamos calcitonina (CT) sérica, marcador bioquímico do CMT, por métodos distintos (RIA e IRMA) em 60 casos (55 mulheres; com idades entre 22 e 75 anos). A análise citológica obtida através de punção biópsia (PAAF) revelou 100 por cento de especificidade e 67 por cento de sensibilidade na detecção de carcinoma de tireóide. Considerando-se o grau de suspeita clínica para neoplasia tireoideana e os achados anatomopatológicos, houve 60 por cento de correlação positiva. CMT foi diagnosticado através da elevação da CT sérica em um dos 59 casos (1,69 por cento) e confirmado posteriormente pela PAAF e anatomopatológico. A incidência de CMT entre os casos de neoplasias tireoideanas nesta amostra foi de 12,5 por cento (1/8). Concluímos que a dosagem rotineira da CT sérica em casos com BUS não só complementa o estudo desta doença, como auxilia fortemente no diagnóstico do CMT. Tanto o IRMA como o RIA mostraram-se métodos úteis no rastreamento do CMT. Entretanto, o RIA pode provavelmente detectar ainda mais precocemente a elevação de formas não monoméricas da molécula de CT, as quais nos casos de CMT são usualmente mais abundantes que as formas monoméricas.

Detecçäo precoce do carcinoma medular de tireóide / Early detection of the medullary thyroid carcinoma

Vinte e oito parentes de 11 pacientes com carcinoma medular de tiróide (CMT) foram testados, sendo que dois destes 11 pacientes apresentavam neoplasia endócrina múltipla tipo II. O teste combinado constou de infusäo endovenosa de 2mg de Ca++/kg de peso por 60seg, seguida imediatamente de infusäo de 0,5mcg de pentagrastrina/kg de peso, por 5seg . A calcitonina (CT) sérica foi dosada aos 0, 2, 5 e 10min. Os valores máximos da CT sérica em indivíduos normais foram considerados como 95 e 350pg/ml, em condiçöes basais e após estímulo, respectivemente. Diante de valores anormalmente elevados de CT durante o primeiro teste, um segundo teste foi realizado para confirmar o diagnóstico de hipersecreçäo do CT. Em dois entre 28 casos, estudados, fêz-se o diagnóstico precoce do CMT pelos níveis excessivemente elevados da CT, visto ser este o marcador específico desta neoplasia. A tireoidectomia total e a limpeza ganglionar preventiva foram indicadas em ambos os casos. Os achados patológicos e da imunocitoquímica confirmaram a presença do CTM nos dois casos. Nestes casos, após a cirurgia, os níveis de CT sérica se mantiveram constantemente normais até o presente (18 meses após a cirurgia). Estes achados reforçam a hipótese de cura do CMT em ambos casos. O feocromocitoma e o hiperparatireoidismo foram investigados nos 28 casos, sendo que em dois o hiperparatiroidismo foi suspeitado e está sob atual investigaçäo. Sumarizando, documentou-se a importància do aprofundamento no estudo de parentes de pacientes com CMT, por meio de dosagem de CT. Este procedimento pode levar ao diagnóstico e tratamento precoces desta neoplasia, permitindo eventual cura do paciente.