Effect of BRAF V600E mutation detection of fine-needle aspiration biopsy on diagnosis and treatment guidance of papillary thyroid carcinoma

ObjectiveThe aim of this study was to evaluate the diagnostic value of detection of BRAF V600E mutation in the fine-needle aspiration cytology (FNAC) specimens of thyroid nodules and the relationship between BRAF V600E mutation and the clinicopathological characteristics of papillary thyroid carcinoma (PTC).MethodsA total of 252 patients who underwent initial thyroid surgery were retrospectively analysed. All the patients underwent a preoperative FNAC at our institution, and the thyroid puncture cell fluid was used for both the cytological diagnosis and BRAF V600E mutational analysis using quantitative polymerase chain reaction. The Cochran-Mantel-Haenszel test was used to evaluate the diagnostic value of BRAF V600E mutation in FNAC fluid in diagnosing PTC. The association between BRAF V600E mutation and the clinicopathological parameters of PTC was analysed using the χ² test.ResultsThrough FNAC, 21 (8%), 60 (24%), and 171 (68%) cases were cytologically diagnosed as benign, indeterminate, and malignant, respectively. Postoperatively, 242 cases were histopathologically diagnosed as PTCs and 10 as goitre nodules. In the FNAC samples, 12 (57 %) of the 21 benign, 48 (80 %) of the 60 indeterminate, and 152 (88.9 %) of the 171 malignant cases showed BRAF V600E mutation. The histopathological diagnosis was used as the gold standard. The sensitivity and specificity of BRAF V600E mutational analysis in the FNAC samples for the diagnosis of PTC were 91.7 % and 100 % in benign, 82.8 % and 100 % in the indeterminate, and 89.4 % and 100 % in the malignant cases, respectively.ConclusionBRAF V600E mutational analysis in FNAC samples of thyroid nodules can be used an effective supplementary diagnostic method at our institution. However, BRAF V600E mutation was not associated with aggressive characteristics in PTC.     

Alcian blue and epithelial membrane antigen are useful markers in differentiating benign from malignant papillae in thyroid lesions

Summary Immunohistochemistry for epithelial membrane antigen (EMA) and histochemistry for alcianophilic substances were performed in 17 cases of papillary thyroid carcinoma (PTC) and 11 cases of benign thyroid lesions showing papillary changes (7 diffuse hyperplastic goitres-Graves'disease; 4 colloid cystic goitres). In all PTCs the glycocalix of the cells lining the papillary structures was stronly positive with anti-EMA antiserum. Alcian blue pH 2.5 stain (AB 2.5) was also positive in 15 of these cases. In contrast, no cases of benign thyroid lesions showed AB 2.5 positivity in the cells lining the papillary structures and the positivity with anti-EMA antiserum, present in only 5 out the 11 cases, was focal and very weak. These results indicate that the presence and distribution of EMA and alcianophilic substances may be useful in distinguishing benign from malignant thyroid lesions containing papillae.     

Expression of matrix metalloproteinases in benign and malignant follicular thyroid lesions

AIMS: To examine expression of matrix metalloproteinases (MMPs) and related proteins in follicular thyroid lesions (FTLs) and to determine their usefulness for differential diagnosis of FTLs, particularly between minimally invasive carcinoma and adenoma. METHODS AND RESULTS: Six widely invasive follicular carcinomas (WIFCs), 15 minimally invasive follicular carcinomas (MIFCs), 19 follicular adenomas (FAs) and 10 adenomatous goitres (AGs) were analysed immunohistochemically for MMP-1, MMP-2, MMP-7, MMP-9, membrane-type 1-MMP (MT1-MMP) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). MMP-1 was positive in all FTLs. MMP-2 and MMP-7 were positive in more than 80% of WIFC and MIFC cases, whereas they were negative in all FA and AG cases except one MMP-2+ FA (P < 0.001). MMP-9 stained positive significantly more in MIFC than FA or AG cases (P < 0.05, respectively). The positivity of MT1-MMP and TIMP-2 was different among some of the FTLs, but with no significant difference between MIFC and FA cases. In-situ hybridization of MMP-2 and MMP-7 mRNA in selected cases demonstrated the expression of these enzymes in the tumour cells as well as in some stromal cells. CONCLUSIONS: Our results confirm MMP expression mainly in malignant FTLs and suggest that MMP-2 and MMP-7 may be useful markers to distinguish MIFC from FA.     

Expression of sodium iodide symporter in benign and malignant human thyroid tissues

The extent of human sodium iodide symporter (hNIS) expression in different kinds of human thyroid cancer tissues and cell lines remains controversial. In this study, polyclonal antibodies to hNIS were used to analyze the expression of symporter protein in benign and malignant human thyroid tissues. Formalin-fixed, paraffin wax-embedded tissue sections were used. Staining was performed using primary polyclonal antibody of rabbit anti-human hNIS diluted in PBS (1:500). Results showed that 2 of 3 normal tissue, 3 of nodular hyperplasia, one follicular adenoma, 3 of 11 papillary thyroid carcinoma, 1 of 5 follicular carcinoma and none of 3 metastatic thyroid epithelial tissue specimens stained positively for hNIS. A higher percentage of positive staining for symporter protein was found in benign thyroid tissues including normal thyroid tissue, nodular hyperplasia, and adenoma (60%). In contrast, papillary and follicular thyroid carcinomas demonstrated lower symporter protein expression (20%). In conclusion, although the number of tissue samples examined in this study was small, hNIS staining found a higher ratio of symporter protein expression in normal and benign thyroid tissues compared with malignant tissues. Determination of the reason for discrepancies in the expression of hNIS in in vivo and in vitro studies will require further investigation.     

B-RAF mutations in the etiopathogenesis, diagnosis, and prognosis of thyroid carcinomas

The very recent discovery of B-RAF point mutations as the most prevalent genetic alteration in papillary thyroid carcinoma has revolutionized the molecular knowledge of thyroid malignancies. In this review, we address the role played by such mutations in the etiopathogenesis, diagnosis, prognosis, and therapy selection of thyroid cancer, with an emphasis on papillary carcinoma.     

Septin 7 immunoexpression in papillary thyroid carcinoma: A preliminary study

Papillary thyroid carcinoma (PTC) is the most common type among thyroid cancers. The diagnosis of PTC may be challenging when follicular variant (FVPTC) of this disease is present due to the resemblance of nuclear properties of the classical type (CVPTC). However, making use of ancillary molecular markers in the diagnosis of PTC may help. In our study, we aimed to evaluate the SEPT7 protein expression in PTC. A total of 55 paraffin block tissue samples comprising encapsulated FVPTC (FVPTC(e), n = 25), and CVPTC (n = 15), and benign hyperfunctioning thyroid nodules (HypN, n = 15) were used in this study. Nuclear, cytoplasmic, and overall (total) SEPT7 protein expression levels were determined by using immunohistochemistry. Nuclear, cytoplasmic, and overall SEPT7 expressions (p = 0.02, p = 0.001, p = 0.002, respectively) were significantly lower in FVPTC(e) tissues when compared to HypN. In CVPTC group, nuclear expression was significantly lower (p = 0.004) while overall and cytoplasmic expressions were not changed (p > 0.05). In HypN group, highest nuclear (mean = 2.73), cytoplasmic (mean = 2.86), and overall (mean = 2.86) expression scores were detected. Significantly lower SEPT7 expression in all expressional categories in FVPTC(e) group may be a sign of different molecular signature in this type of tissue.     

Immunohistochemical analysis of nm23 protein expression in thyroid papillary carcinoma and follicular neoplasm

Introduction

We aimed at assessing the significance of nm23 gene expression in papillary and follicular carcinomas, the two most common differentiated thyroid carcinomas.

Materials and methods

During a cross-sectional study, 173 paraffin blocks, including 131 papillary thyroid carcinomas, 12 follicular carcinomas and 30 follicular adenomas were stained with nm23 marker by immunohistochemistry method. Cytoplasmic staining in more than 10% of the tumor cells was considered as positive, and α<0.05 was established as the level of statistical significance for the evaluation of the correlation between nm23 expression and age, sex, tumor size, vascular /capsular invasion and lymph node involvement.

Results

nm23 was positive in 40% of the follicular adenoma, 67.2% of the papillary carcinoma and 66.7% of the follicular carcinoma. p value was more than 0.05 in the assessment of the relationship between nm23 and all of the above-mentioned parameters in differentiated thyroid carcinomas. nm23 expression did not significantly differentiate between follicular adenoma and carcinoma.

Conclusion

According to our results, there is no relationship between nm23 immunoreactivity and age or sex of the patients. Also, nm23 cannot be considered as a useful marker for the evaluation of invasion in differentiated thyroid carcinomas or in distinctions between follicular adenoma and carcinoma.     

How to define follicular thyroid carcinoma?

The appropriate diagnosis of follicular thyroid carcinoma (FTC) still depends on its histological discrimination from follicular adenoma (including the distinction of benign from malignant oncocytic variants), papillary thyroid carcinoma (particularly from the follicular variants) and poorly differentiated thyroid carcinoma. The use of immunohistochemical markers contributed only marginally to better defining FTC. The introduction of the micro array technique, however, may offer the possibility of getting a better insight into the natural history, as well as predicting the clinical course, of a given thyroid nodule. This review attempts to recapitulate common standards in the diagnosis of FTC, to summarise current molecular data available to distinguish FTC from other benign and malignant tumours and, finally, to outline future perspectives to define FTC on its specific genetic features.     

Renal-cell carcinoma with intranuclear inclusions metastatic to thyroid: a diagnostic problem in aspiration cytology

A case of renal-cell carcinoma (RCC) exhibiting prominent intranuclear inclusions in a metastasis to the thyroid is presented. RCC had been treated in this patient by right nephrectomy 7 yr earlier and by left partial nephrectomy 5 yr earlier; the patient had also received radiation to the neck 4 yr earlier for carcinoma in situ of the left true vocal cord. Aspiration performed on a rapidly enlarging mass in the left lobe of the thyroid revealed both clusters of tumor cells and single tumor cells with prominent intranuclear inclusions. Definitive distinction between a primary and metastatic neoplasm was difficult on the aspiration specimen. Subsequent thyroidectomy confirmed the diagnosis of metastatic renal-cell carcinoma with intranuclear inclusions by histologic, immunohistochemical, and ultrastructural analysis. The differential diagnosis by aspiration cytology of thyroid neoplasms that contain intranuclear inclusions is discussed.     

Identification of immunohistochemical biomarkers for papillary thyroid carcinoma using gene expression profiling

We report the successful validation of a combined gene expression profiling and tissue microarray approach to papillary thyroid carcinoma (PTC) biomarker identification. Our ultimate goal is the identification of protein biomarkers that can be effectively used in immunocytochemical assays applied to thyroid fine needle aspiration biopsy (FNAB) samples. To that end, we designed our approach to prioritize molecules that were minimally expressed in normal thyroid and highly expressed in PTC. We first generated gene expression profiles from 11 normal thyroid tissue samples and 9 samples of classic PTC. The results were segregated to rank most highly those molecules not expressed in normal thyroid and up-regulated at least 6-fold in PTC. From this list, we chose 2 molecules (P-cadherin and Bax) for immunohistochemical analysis for which commercial antibodies were available. These were compared with 2 other molecules that have been previously studied in thyroid cancer (cytokeratin-19 and galectin-3). For immunohistochemistry, a tissue microarray was generated that contained the following tissues: classic PTC (n = 20), follicular variant of PTC (n = 9), normal thyroid (n = 19), Hashimoto thyroiditis (n = 11), follicular adenoma (n = 15), and follicular carcinoma (n = 14). Immunohistochemical staining was scored and compared with the gene expression profiling. As anticipated, cytokeratin-19 and galectin-3 were highly expressed in PTC and less expressed in other tissues. Bax and P-cadherin were also expressed in PTC, but to a lower level than cytokeratin-19 and galectin-3; however, Bax and P-cadherin demonstrated virtually no staining of normal thyroid, unlike cytokeratin-19 and galectin-3. These results validate our approach for PTC biomarker discovery and identify several candidate biomarkers for further development.     

Thyroid neoplasms of follicular cell derivation: A simplified approach

Thyroid tumors of follicular cell derivation are increasing in incidence. These lesions exhibit a spectrum of morphologic and behavioral features that provide the opportunity to understand malignant transformation and progression. Molecular data suggest that the thyroid undergoes a series of genetic alterations that account for the development of the various types of thyroid carcinoma. Our understanding of these tumors has progressed dramatically over the past 50 years and the classification has become complex and cumbersome. We provide a practical approach to clinical diagnosis and propose a simplified classification of these common neoplasms.     

Supportive role of image analysis and DNA ploidy pattern in the diagnosis of thyroid tumors.

To evaluate the supportive role of image cytometry and DNA ploidy pattern in the diagnosis of thyroid tumors, a preliminary study was performed on fine needle aspirates of 30 cases. Of these, 10 cases each were of colloid goiter, follicular neoplasm, and papillary carcinoma. The nuclear area and DNA value of 50 cells in each case were measured. The mean nuclear area in colloid goiter (69.50 + 12.62 sq.microns) was significantly lower than the mean nuclear area in a follicular neoplasm (88.71 + 15.51 sq.microns) (P less than 0.05). Similar differences between the mean nuclear area in colloid goiter and papillary carcinoma (124.0 + 12.27 sq microns) was also highly significant (P less than 0.001). The results obtained by image cytometry were compared with estimated DNA ploidy pattern of follicular cells from the same cases. All colloid goiter had mean nuclear area below 100 sq.microns with diploid DNA value. However, papillary carcinoma showed aneuploid DNA pattern in eight cases (80.0%), but mean nuclear area was above 100 sq.microns. A diagnostically useful finding obtained in two of the 10 cases of follicular neoplasm was the association of aneuploid DNA pattern with mean nuclear area of the follicular cells above 100 sq.microns indicating a high probability of carcinoma and thus demanding an urgent open biopsy. These cases were readily distinguished from other cases of the same category showing diploid DNA pattern and mean nuclear area of follicular cells below 100 sq.microns.     

The encapsulated follicular carcinoma of the thyroid

Summary In a retrospective study of 86 follicular carcinomas of the thyroid gland, 35 lesions were classified as encapsulated carcinomas (40.7%). In two of these, lymph node metastases were detected initially. Another patient presented with distant metastases. The biological behaviour of these 35 tumours was studied over a long-term follow-up period (0.4–19.1 years, mean 10.3 years) which featured three cases of death from thyroid carcinoma 0.4–5.0 years after thyroidectomy. Another patient suffered from local recurrence of a follicular carcinoma 13.9 years later. The morphological and clinical findings of those five patients who initially presented with metastases and/or whose follow-up registered the local recurrence of thyroid cancer or death as a result of it, were compared with the remaining 30 cases which were of a benign clinical course. Statistical analysis showed that the prognosis of encapsulated follicular carcinoma is more serious when tumours occur in patients older than 65 years of age and when the tumour diameter is 5.0 cm or more. There was a tendency towards poorer prognosis in those tumours exclusively composed of oxyphilic epithelium.Sponsored by: Hamburger Stiftung zur Förderung der Krebsbekämpfung     

Papillary thyroid carcinomas

Summary It is generally believed that the histological pattern of papillary thyroid carcinomas has no influence on the course of the disease. However, we were puzzled by the evident differences in the clinical course of these tumours and decided to re-examine all microscopic specimens available at the Institute of Pathology of the University of Zürich. These had been obtained from 169 surgical cases operated on between 1962 and 1977. We classified the material according to precise morphological criteria and matched it with a number of clinical and catamnestic data in order to determine which parameters correspond best with the development of the disease. Although the fate of patients below 50 years of age is slightly more favourable than that of older subjects, age is by no means the most important factor. In fact, the prognosis correlates significantly better with the initial local extension of the primary tumour (occult, intrathyroid or extrathyroid). Furthermore, this parameter is closely related to the histological pattern of our various papillary carcinoma subtypes which we graded according to differentiation. All factors considered, the morphological pattern appears to offer a rewarding approach to the provision of an accurate prognosis.     

Occult carcinoma of the thyroid gland

Ten occult carcinomas of the thyroid gland were found in 274 unselected autopsies at the Pathology Service, Hospital José Joaquín Aguirre, between December 1980 and March 1983. This is the lowest incidence among the most recent published series. The present results suggest that environmental factors play an important role in the etiology of this type of carcinoma.