Expressão citofotométrica da Caspase-3 no carcinoma papilífero da tireóide e no bócio colóide / Citophotometric expression of Caspase-3 in papillary thyroid carcinoma in nodular goiter colloid

OBJETIVO: Descrever a expressão citofotométrica quantitativa do marcador caspase-3 no bócio colóide e no carcinoma papilífero da tireóide e comparar a imunoexpessão entre as doenças. MÉTODOS: Realizou-se estudo imunoistoquímico da proteína caspase-3 em 17 blocos de parafina de carcinoma papilífero da tiróide e 20 de bócio colóide, através do sistema SAMBA 4000 - (Sistema de análise microscópica de busca automática), objetivando-se analisar duas variáveis: índice de marcagem e densidade óptica. RESULTADOS: Houve diferença significativa quanto ao índice de marcagem da caspase-3, entre o bócio colóide e o carcinoma papilífero, sendo maior no carcinoma, e não foi encontrada diferença significativa quanto à densidade óptica. Para o bócio colóide, o coeficiente de correlação estimado entre o índice de marcagem e a densidade óptica foi igual a 0,72, indicando assim, a rejeição da hipótese nula (p <0,001), afirmando-se que existe associação positiva e significativa entre o índice de marcagem e a densidade óptica da caspase-3. Para o carcinoma papilífero da tiróide, o coeficiente de correlação estimado entre o índice de marcagem e a densidade óptica 3 foi de 0,34. O resultado do teste estatístico indicou que não se pode afirmar que existe associação entre esses parâmetros. CONCLUSÃO: Para o bócio colóide existe associação positiva e significativa entre as duas variáveis, índice de marcagem e a densidade óptica da caspase-3, enquanto que para o carcinoma papilífero não existe essa associação. O estudo comparativo entre a análise quantitativa da caspase-3, demonstrou que a apoptose é mais evidente no carcinoma papilífero do que no bócio colóide.

OBJECTIVE: To describe quantitative cytophotometric expression of the marker caspase-3 in colloid goiter and in papillary carcinoma of the thyroid, comparing the immunoexpression between them. METHODS: An immunohistochemistry study has been made on the protein caspase-3 in 17 of paraffin blocks of papillary carcinoma of the thyroid and 20 cases of colloid goiter, using SAMBA 4000 ® (System of Microscopic Analysis of Automatic Search), aiming analysis of the two variables: marker index and optical density. RESULTS: Statistic analysis indicated a significant difference for marker index between colloid goiter and papillary carcinoma, being this difference larger in the carcinoma. It hasn't been found significant difference in optical density. For colloid goiter, the estimated correlation coefficient between the marker index and optical density was 0,72, indicating the rejection of the null hypothesis (p <0,001), affirming that positive and significant association exists between them. For the papillary carcinoma of the thyroid, the same correlation was 0,34 and so, it is not possible to affirm that there's an association between them. CONCLUSION: For colloid goiter there is a positive and significant association between the two variables - marker index and optical density -, while for the papillary carcinoma, this is not proved. The quantitative analysis for caspase-3 demonstrates that apoptosis is larger in the papillary carcinoma of the thyroid than in colloid goiter.

Diagnostic Value of Galectin-3, HBME-1, Cytokeratin 19, High Molecular Weight Cytokeratin, Cyclin D1 and p27(kip1) in the Differential Diagnosis of Thyroid Nodules

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27(kip1) in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC).The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC.

Hyalinizing trabecular adenoma--a case report with FNAC histologic, MIB-1 proliferative index and immunohistochemical findings.

Hyalinizing trabecular adenoma is a recently described benign thyroid tumor, almost exclusively occurring in females. The morphological features of this entity overlap with both papillary and medullary carcinoma to varying extent. This, in turn, creates a situation of serious diagnostic pitfall particularly for a false positive diagnosis of papillary carcinoma in fine needle aspiration (FNA) cytology. False consideration of medullary carcinoma is also possible by the unwary especially if staining for Congo red and/or immunostaining for calcitonin is not resorted to. At histologic level, the distinctive architectural pattern is however of great help and thus poses a much lesser danger of misdiagnosis. We relate here our experience in a recently encountered case of hyalinizing trabecular adenoma and describe detailed FNA cytologic and histologic findings along with immunohistochemical profile using a panel of eight monoclonal antibodies. The tumor proliferative potential has also been assessed using MIB-1 (Ki-67) immunostaining. The various pros and cons of diagnostic pitfalls are discussed.

Autoradiographic thyroid evaluation in short-term experimental diabetes mellitus

Previous studies have shown that in vitro thyroid peroxidase (TPO) iodide oxidation activity is decreased and thyroid T4-5' -deiodinase activity is increased 15 days after induction of experimental diabetes mellitus (DM). In the present study we used thyroid histoautoradiography, an indirect assay of in vivo TPO activity, to determine the possible parallelism between the in vitro and in vivo changes induced by experimental DM. DM was induced in male Wistar rats (about 250 g body weight) by a single ip streptozotocin injection (45 mg/kg), while control c animals received a single injection of the vehicle. Seven and 30 days after diabetes induction, each diabetic and control animal was given ip a tracer dose of I (2 muCi), 2.5 h before thyroid excision. The glands were counted, weighed, fixed in Bouin's solution, embedded in paraffin and cut. The sections were stained with HE and exposed to NTB-2 emulsion (Kodak). The autohistograms were developed and the quantitative distribution of silver grains was evaluated with a computerized image analyzer system. Thyroid radioiodine uptake was significantly decreased only after 30 days of DM (C:0.38 + 0.05 vs DM: 0.20 + 0.04 percent/mg thyroid, P<0.05) while in vivo TPO activity was significantly decreased 7 and 30 days after DM induction (C:5.3 and 4.5 grains/100 mum2 vs DM: 2.9 and 1.6 grains/100 mum2, respectively, P<0.05). These data suggest that insulin deficiency first reduces in vivo TPO activity during short-term experimental diabetes mellitus.

Ioduria en escolares. Relacion con incidencia de bocio, nivel socioeconomico e ingesta de sal / Iodine in school children. Relationship with incidence of goiter, socioeconomic group and salt intake

Para valorar la ingesta diaria de iodo se midió la ioduria en 134 escolares de ambos sexos, de 5 - 14 años, de Luján de Cuyo (Mendoza). Los mismos fueron categorizados: a) según la existencia o no de bocio por palpación de 2 observadores; b) según el nivel socioeconómico y c) según la marca comercial de sal consumida. Las muestras provenían de un grupo examinado de 700 escolares. No hubo diferencias significativas en sexo, edad, peso o estatura entre los grupos mencionados. Se recolectaron m-uestras de escolares bociosos en mayor proporción que de normales. La ioduria media de los escolares sin bocio fue significativamente mayor que la de los bociosos, (p < 0,005). La prevalencia de bocio disminuyó en los escolares con ioduria de > 150 mug/24 h (p < 0,05). Los niveles de ioduria de escolares de distinto nivel socioeconómico fueron semejantes (p = 0,56). No se encontraron diferencias significativas entre consumidores de las dos marcas comerciales de sal más comunes (p = 0,07). Aunque los valores medios de ioduria en la población evaluada son aceptables, la amplia variabilidad observada sugiere la implementación de mejores medidas de control y de información a la población y, tal vez, la suplementación de iodo discriminada para optimizar la iodoprofilaxis.