Tall cell variant of papillary thyroid carcinoma without extrathyroid extension: Biologic behavior and clinical implications
ABSTRACT The tall cell variant (TCV) is a histologic subtype of papillary thyroid carcinoma (PTC) that is more aggressive than "classical" PTC. Most authors believe that TCV's worse prognosis is related to older age at presentation, larger tumor size, and high frequency of extrathyroid tumor extension (ETE). To assess the biologic and clinical behavior of TCV without ETE, we performed a detailed comparative clinicopathologic analysis of classical PTC and TCV without ETE.
TCV was defined as a PTC harboring >50% tall cells, while classical PTC was restricted to those tumors containing >1% papillae and <30% tall cells. Microscopic analysis and chart review identified 62 cases of TCV and 83 classical PTC without ETE. These patients were analyzed for various pathologic, imaging, and clinical parameters including outcome.
There was no statistical difference between TCV and classical PTC in relation to age, gender, tumor size, risk stratification, type of therapy, and length of follow-up. TCV displayed more invasion of the tumor capsule and more often infiltrated into the thyroid capsule (p = 0.047 and 0.0004, respectively). Among patients with microscopically assessable regional lymph node (LN), 33 of 49 (67.3%) patients with TCV had LN metastasis at presentation, while only 24 of 60 (40%) classical PTC had positive nodes (p = 0.004). In multivariate analysis, histologic subtype (TCV vs. classical PTC) was the only independent factor associated with LN metastases (p = 0.007). In patients with adequate follow-up, 4 of 62 (6.5%) classical PTC and 7 of the 47 (14.9%) TCV had thyroid cancer recurrence (p = 0.202). TCV recurred at a distant site (3 of 47, 6.4%) while none of the 62 classical PTC developed distant metastases (p = 0.077).
TCV without ETE is biologically a more aggressive tumor than classical PTC without ETE independent of age, gender, and tumor size.
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ABSTRACT: Objective. To evaluate the prognosis of tall cell variant (TCV) compared to usual variant (UV) papillary thyroid cancer by comparing disease-related mortality and recurrence data from published studies. Methods. Ovid MEDLINE keyword search using "tall cell variant papillary thyroid cancer" was used to identify studies published in English that calculated disease-related mortality and recurrence rates for both TCV and UV. Results. A total of 131 cases of tall cell variant papillary thyroid cancer were reviewed. The combined odds ratio of recurrence for TCV compared to UV is 4.50 with a 95% confidence interval from 2.90 to 6.99. For disease-related mortality, the combined odds ratio for TCV was compared to UV of 14.28 with a 95% confidence interval from 8.01 to 25.46. Conclusion. Currently published data suggests that TCV is a negative prognostic indicator in papillary thyroid cancer and requires aggressive therapy. This meta-analysis provides the largest prognostic data series on TCV in the literature and clearly identifies the need for accurate pathological identification of TCV and its further study as an independent prognostic factor.07/2010; 2010:325602. DOI:10.4061/2010/325602
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ABSTRACT: Dissertação (mestrado)—Universidade de Brasília, Faculdade de Medicina, 2008. Apesar da punção aspirativa por agulha fina da tireóide ser o melhor teste propedêutico na avaliação do nódulo tireoidiano, existem casos suspeitos que não podem ser definidos citologicamente como malignos ou benignos. Diante desses casos indefinidos, os cirurgiões optam pela tireoidectomia, não por um ato terapêutico, mas diagnóstico. O resultado disso é que a maioria dos nódulos suspeitos é operada e, no exame histopatológico, mais de dois terços são classificados como benigno (bócios, hiperplasias e adenomas), tendo o procedimento cirúrgico sido realizado sem necessidade, portanto gerando grandes gastos hospitalares e causando eventuais morbidades relacionadas com a cirurgia radical da tireóide. A partir disso buscou-se ao longo dos anos, um marcador molecular que diferenciasse, nos esfregaços citológicos, quais materiais eram provenientes de nódulos benignos ou malignos. A galectina-3 é apontada pela literatura com um dos principais candidatos para essa função. Para se testar essa hipótese foi feito um estudo retrospectivo para pesquisa da galectina-3, através de imunohistoquímica, em produtos de tireoidectomia. Foram selecionados 15 casos de bócio adenomatoso, 24 de adenoma folicular, 29 de carcinoma papilar e 22 de carcinoma folicular. A expressão da galectina-3 foi comparada com o diagnóstico histopatológico (padrão-ouro). Os valores para a sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, acurácia diagnóstica, "Likelihood Ratio" Positiva e "Likelihood Ratio" Negativa da positividade citoplasmática foram respectivamente de 92,16%, 94,38%, 90,38%, 95,45%, 93,57%, 16,40 e 0,08. Após correção da prevalência para 5%, o valor preditivo positivo, valor preditivo negativo e acurácia diagnóstica passaram a ser 46,33%, 99,56% e 94,27%. Esses dados, obtidos em preparados histológicos, sugerem que a pesquisa da galectina-3 em esfregaços citológicos poderá ser um importante auxílio para a definição diagnóstica. ____________________________________________________________________________________ ABSTRACT Fine needle aspiration biopsy is considered to be the best propedeutic method used in evaluation of a thyroid nodule. However, in some situations, it is impossible to cytologically distinguish a malignant and a begnin disease; therefore, surgeons must indicate thyroidectomy for a diagnostic purpose. This results that most suspect nodules are referred to surgery and, in histopathologic analysis, more than two thirds are considered begnin (goiters, hiperplasis and adenomas). This situation lead to a search for a molecular marker that could discriminate, on cytological smers, those obtained from malignant nodules. Galectin-3 is considered a strong candidate for that function. To best this hypothesis a retrospective study was conducted in order to evaluate the expression of galectin-3 in thyroidectomy specimens using immunohistochemistry. Fifteen cases of nodular goiter, 24 of follicular adenoma, 29 of papillary carcinoma and 22 of follicular carcinoma were selected. Galectin-3 expression was compared to histopathologic diagnosis (gold-standard). Values for sensibity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, positive likelihood ratio, negative likelihood ratio were 92,16%, 94,38%, 90,38%, 95,45%, 93,57%, 16,40%, and 0,08. Prevalence of disease was corrected for 5% leading to positive predictive value, negative predictive value, diagnostic accurary of 46,33%, 99,56% and 94,27%. This data, seggest that galectin-3 could be an important aid in diagnostic definition.
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ABSTRACT: Thyroid cancer is the most common endocrine malignancy and its incidence is increasing [1, 2]. Differentiated thyroid cancer consists of papillary, follicular, and Hurthle cell histological types. Although it typically has a good prognosis due to its long, indolent, and well-tolerated natural history, lifelong follow-up is recommended as late recurrences may occur after surgery. Advances in diagnostic modalities and pathologic analysis continue to evolve. High-resolution ultrasound plays an increasingly important role in the management of thyroid cancer, including diagnosis of malignancy, preoperative lymphatic mapping and postoperative surveillance. Surgery remains the mainstay of therapy; however, thyroid suppression and radioactive iodine ablation also contribute to the treatment. The first section of this chapter contains an overview of the clinical characteristics of well-differentiated thyroid cancer including risk factors, symptoms, diagnosis, histologic types, management and follow-up strategies. The second part will provide a more detailed evaluation of the effects of the Chernobyl nuclear accident on the subsequent development of well-differentiated thyroid cancer.