HBME-1 is the most sensitive marker for thyroid malignancy but the three markers may be useful in specific cases. This panel of markers is useful to differentiate the follicular patterned lesions, with special reference to the FVPC.

Thyroid nodules are frequent findings, especially when sensitive imaging methods are used. Although thyroid cancer is relatively rare, its incidence is increasing, particularly in terms of small tumors, which have an uncertain clinical relevance. Most patients with differentiated thyroid cancer exhibit satisfactory clinical outcomes when treatment is appropriate, and their mortality rate is similar to that of the overall population. However, relapse occurs in a considerable fraction of these patients, and some patients stop responding to conventional treatment and eventually die from their disease. Therefore, the challenge is how to identify the individuals who require more aggressive disease management while sparing the majority of patients from unnecessary treatments and procedures. We have updated the Brazilian Consensus that was published in 2007, emphasizing the diagnostic and therapeutic advances that the participants, representing several Brazilian university centers, consider most relevant in clinical practice. The formulation of the present guidelines was based on the participants' experience and a review of the relevant literature. Arq Bras Endocrinol Metab. 2013;57(4):240-64 Keywords Thyroid nodules; thyroid cancer; Brazilian consensus; update RESUMO Nódulos tireoidianos são muito frequentes, sobretudo quando se empregam métodos sensí-veis de imagem. Embora o câncer seja proporcionalmente raro, sua incidência vem aumentando, especialmente de tumores pequenos, cuja evolução clínica é incerta. A maioria dos pacientes com carcinoma diferenciado de tireoide evolui bem quando adequadamente tratada, com índices de mortalidade similares à população geral. Por outro lado, um percentual não desprezível apresenta recidivas e alguns eventualmente não respondem às terapias convencionais, evoluindo para óbito. Assim, o desafio é distinguir os pacientes merecedores de condutas mais agressivas e, ao mesmo tempo e não menos importante, poupar a maioria de tratamentos e procedimentos desnecessários. Atualizamos o Consenso Brasileiro publicado em 2007, ressaltando os avanços diagnósticos e terapêuticos que os participantes, de diferentes Centros Universitários do Brasil, consideram mais relevantes para prática clínica. A elaboração dessas diretrizes foi baseada na experiência dos participantes e revisão da literatura pertinente. Arq Bras Endocrinol Metab. 2013;57(4):240-64 Descritores

Our data suggest that the tumour or peri-tumoural microenvironment may act to modify the observed pattern of immune response. Immune cell infiltration and the presence of concurrent CLT helped characterize specific tumour histotypes associated with favourable prognostic features.

The aims of these recommendations were to develop clinical guidelines for evaluation and management of patients with differentiated thyroid cancer applicable to Latin American countries. The panel was composed by 13 members of the Latin American Thyroid Society (LATS) involved with research and management of thyroid cancer from different medical centers in Latin America. The recommendations were produced on the basis of the expert opinion of the panel with use of principles of Evidence-Based Medicine. Following a group meeting, a first draft based on evidences and the expert opinions of the panel was elaborated and, later, circulated among panel members, for further revision. After, this document was submitted to the LATS members, for commentaries and considerations, and, finally, revised and refined by the authors. The final recommendations presented in this paper represent the state of the art on management of differentiated thyroid cancer applied to all Latin American countries. Arq Bras Endocrinol Metab. 2009;53(7):884-97. KeywordśThyroid cancer; thyroid ultrasonography; radioiodine therapy; thyroglobulin; consensus RESUMO Estas recomendações tiveram por objetivo o desenvolvimento de diretrizes para avaliação e manejo de pacientes com câncer diferenciado da tiroide em países latino-americanos. Um painel composto por 13 membros da Sociedade Latino-Americana de Tireoide (SLAT) -que estavam envolvidos em pesquisas, e eram peritos no cuidado do paciente com câncer da tiroide e provenientes de diferentes centros médicos latino-americanos -utilizou os princípios da Medicina Baseada em Evidências para produzir esse consenso. Após uma primeira reunião, um texto inicial foi elaborado, baseado em evidências e opiniões dos especialistas do painel e, posteriormente, circulado entre os membros do painel, para revisão. Após a revisão, o documento foi enviado aos membros da SLAT para comentários e considerações e, finalmente, revisado e refinado pelos autores. As recomendações finais aqui apresentadas demonstram o estado da arte no manejo do câncer diferenciado da tireoide aplicadas aos países latino-americanos.Arq InTRODUCTIOn T he risk of malignancy in a thyroid nodule varies between 5% and 10% in iodine sufficient countries, and the amount of iodine supplemented in table salt influences on the morphology of the malignant tumor types (1).

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Loss of heterozygosity (LOH) studies have been used to identify sites harboring tumor suppressor genes involved in tumor initiation or progression. Previous reports have suggested that regions within chromosomes 3p, 11q, 2p, 2q, 10q, and 1p may be frequently deleted in human follicular thyroid cell tumors. We have extended the analysis of these and other selected regions to 65 paired thyroid tumor tissues. Twenty-four were follicular adenomas, 30 were papillary carcinomas, 10 were follicular carcinomas, and 1 was an anaplastic carcinoma. Sixty percent of the follicular carcinomas, 33% of the follicular adenomas, and 23% of the papillary carcinomas presented LOH at least at 1 site. Fifty percent of the follicular carcinomas showed 2 or more chromosome arms affected by deletions, whereas just 1 of the 24 follicular adenomas and none of the papillary carcinomas presented this feature. However, none of the specific loci examined had a rate of LOH greater than 33%, even in follicular carcinomas. This prompted us to place our findings into a broader context, and we, therefore, performed a meta analysis of all published studies of LOH in follicular thyroid neoplasms. There was a phenotype dependency in the overall rate of LOH, with no specific region displaying a particularly high prevalence. Most notably, by contrast to follicular carcinomas, papillary carcinomas had exceedingly low rates of LOH. Thus, there is a sharp distinction between the two major forms of differentiated thyroid cancer in their tendency to lose genetic material. This probably results from a fundamental difference in mechanisms controlling chromosomal stability in these two forms of cancers that in all likelihood has implications for tumor behavior and prognosis.

Immune responses against thyroid carcinomas have long been demonstrated and associations between inflammatory microenvironment and thyroid carcinomas repeatedly reported. This scenario has prompted scientists throughout the world to unveil how the inflammatory microenvironment is established in thyroid tumors and what is its influence on the outcome of patients with thyroid carcinoma. Many studies have reported the role of evasion from the immune system in tumor progression and reinforced the weakness of the innate immune response toward thyroid cancer spread in advanced stages. Translational studies have provided evidence that an increased density of tumor-associated macrophages in poorly differentiated thyroid carcinoma (DTC) is associated with an aggressive phenotype at diagnosis and decreased cancer-related survival, whereas well-DTC microenvironment enriched with macrophages is correlated with improved disease-free survival. It is possible that these different results are related to different microenvironments. Several studies have provided evidence that patients whose tumors are not infiltrated by lymphocytes present a high recurrence rate, suggesting that the presence of lymphocytes in the tumor microenvironment may favor the prognosis of patients with thyroid carcinoma. However, the effect of lymphocytes and other immune cells on patient outcome seems to result from complex interactions between the tumor and immune system, and the molecular pattern of cytokines and chemokines helps to explain the involvement of the immune system in thyroid tumor progression. The inflammatory microenvironment may help to characterize aggressive tumors and to identify patients who would benefit from a more invasive approach, probably sparing the vast majority of patients with an indolent disease from unnecessary procedures.