Differential reactivity of HBME-1 and CD15 antibodies in benign and malignant thyroid tumours. Preferential reactivity with malignant tumours

Galectin-3 and HBME-1 Expression on Agarose Cell Blocks from Fine-needle aspirates of Follicular Cell-derived Thyroid Tumors

Aim:

To test the expression of galectin-3 (gal-3) and Hector Battifora mesothelial antigen-1 (HBME-1) on agarose cell blocks (CBs) of fine-needle aspirates aiming to determine their diagnostic value in thyroid follicle cell-derived tumors.

Materials and Methods:

Forty patients with thyroid nodule were enrolled. Fine-needle aspiration biopsy was done and processed to produce smears and CBs. Immune staining was done on CBs using antibodies to gal-3 and HBME-1. Diagnostic value of tests was determined in comparison to pathology.

Results:

Current study included 17 papillary thyroid carcinoma (PTC), 15 follicular adenoma, and 8 follicular thyroid carcinoma (FTC). In PTC diagnosis, co-expression of gal-3/HBME-1 had a sensitivity of 94.1%, specificity of 73.3%, positive predictive value (PPV) of 80%, negative predictive value (NPV) 91.7%, and accuracy of 84.4%. In FTC diagnosis, combined gal-3/HBME-1 expression had a sensitivity of 75%, specificity of 78.6%, PPV of 50%, NPV of 91.7%, and accuracy of 77.8%. Co-expression of gal-3/HBME-1 raised the sensitivity of detection of differentiated thyroid carcinomas from 40% with cytomorphology to 92% and accuracy from 62.5% to 85%.

Conclusion:

The combined immunocytochemical expression of gal-3 and HBME-1 utilizing fine-needle aspirates can improve the sensitivity of detection and diagnostic accuracy of differentiated follicular cell-derived thyroid carcinomas.

Application of Immunocytochemistry on Cell Block Sections for the Investigation of Thyroid Lesions

OBJECTIVE

To investigate the potential of Classification and Regression Trees (CARTs) for the diagnosis of thyroid lesions based on cell block immunocytochemistry and cytological outcome.

STUDY DESIGN

A total of 956 histologically confirmed cases (673 benign and 283 malignant) from patients with thyroid nodules were prepared via liquid-based cytology and evaluated; 4 additional slides were stained for cytokeratin 19 (CK-19), galectin 3 (Gal-3), Hector Battifora mesothelial cell 1 (HBME-1), and thyroglobulin. On the basis of immunocytochemistry and the cytological diagnosis, a CART algorithm was constructed and used for evaluation.

RESULTS

The major important factors contributing to the diagnostic CART model were: cytological outcome, CK-19, Gal-3, and HBME-1. The sensitivity and specificity of the cytological diagnosis were 96.27% and 88.26%, respectively (cut-off: category 3 of The Bethesda System [TBS-3]). The introduction of immunocytochemistry and the CART model increased the sensitivity and specificity to 98.88% and 99.11%, respectively. CK-19 presented the best performance for discriminating papillary thyroid carcinomas, followed by HBME-1 and Gal-3. In the TBS-2 cases, CK-19 and, subsequently, Gal-3 were important immunocytochemistry markers. Ultimately, CK-19 and HBME-1 on TBS-5 or TBS-6 cases demonstrated the best results.

CONCLUSIONS

The hierarchical structure of the CART model provides a diagnostic algorithm linked with the risk of malignancy at every step of the procedure. It also provides guidance on the use of ancillary examinations as it goes by simple, human understandable rules.

Surgical treatment of thyroid follicular neoplasms: results of a retrospective analysis of a large clinical series

The most appropriate surgical management of "follicular neoplasm/suspicious for follicular neoplasm" lesions (FN), considering their low definitive malignancy rate and the limited predictive power of preoperative clinic-diagnostic factors, is still controversial. On behalf of the Italian Association of Endocrine Surgery Units (U.E.C. CLUB), we collected and analyzed the experience of 26 endocrine centers by computerized questionnaire. 1379 patients, surgically treated after a FN diagnosis from January 2012 and December 2103, were evaluated. Histological features, surgical complications, and medium-term outcomes were reported. Total thyroidectomy (TT) was performed in 1055/1379 patients (76.5 %), while hemithyroidectomy (HT) was carried out in 324/1379 cases (23.5 %). Malignancy rate was higher in TT than in HT groups (36.4 vs. 26.2 %), whereas the rates of transient and definitive hypoparathyroidism following TT were higher than after HT. Consensual thyroiditis (16.8 vs. 9.9 %) and patient age (50.9 vs. 47.9 %) also differed between groups. A cytological FN diagnosis was associated to a not negligible malignancy rate (469/1379 patients; 34 %), that was higher in TT than in HT groups. However, a lower morbidity rate was observed in HT, which should be considered the standard of care in solitary lesions in absence of specific risk factors. Malignancy could not be preoperatively assessed and clinical decision-making is still controversial. Further efforts should be spent to more accurately preoperatively classify FN thyroid nodules.

Stage-Specific Embryonic Antigen-1 (SSEA-1) Expression in Thyroid Tissues

Stage-specific embryonic antigen-1 (SSEA-1), also known as CD15, is a member of a cluster of differentiation antigens that have been identified in various normal tissues and in different types of cancers including papillary and medullary thyroid carcinoma. SSEA-1 may be expressed in normal stem cells and cancer stem-like cells. To evaluate the potential diagnostic and prognostic utility of SSEA-1 in thyroid tumors, we analyzed the expression of SSEA-1 in normal and neoplastic thyroid tissues by immunohistochemistry (IHC) using a tissue microarray with 158 different tissue cores. To evaluate the potential utility of SSEA-1 as a surface marker, we also assessed the expression of SSEA-1 in thyroid cell lines by flow cytometric analysis. SSEA-1 immunoreactivity was identified in malignant thyroid follicular epithelial cancers but not in the benign thyroid tissues. Anaplastic thyroid (ATC) (80 %) and conventional papillary thyroid carcinoma (PTC) (60.7 %) showed significantly higher percentage of cases that were SSEA-1 immunoreactive than follicular variant of papillary thyroid carcinoma (FVPTC) (20.6 %) and follicular carcinoma (FCA) (32.1 %). Flow cytometric analysis of cultured thyroid cell lines showed that a small subpopulation of ATC and PTC thyroid tumor cells had SSEA-1 immunoreactivity which may represent thyroid cancer stem-like cells. The ATC cells expressed more SSEA-1 immunoreactive cells than the PTC cell lines. Our findings suggest that expression of SSEA-1 immunoreactivity in thyroid neoplasms was associated with more aggressive thyroid carcinomas. SSEA-1 is a marker that detects malignant thyroid neoplasms in formalin-fixed paraffin-embedded thyroid tissue sections and may be a useful marker for thyroid cancer stem-like cells.

A metabolic phenotype based on mitochondrial ribosomal protein expression as a predictor of lymph node metastasis in papillary thyroid carcinoma

Metabolic reprogramming has been regarded as an essential component of malignant transformation. However, the clinical significance of metabolic heterogeneity remains poorly characterized. The aim of this study was to characterize metabolic heterogeneity in thyroid cancers via the analysis of the expression of mitochondrial ribosomal proteins (MRPs) and genes involved in oxidative phosphorylation (OxPhos), and investigate potential prognostic correlations. Gene set enrichment analysis (GSEA) verified by reverse transcription polymerase chain reaction and gene network analysis was performed using public repository data. Cross-sectional observational study was conducted to classify papillary thyroid cancer (PTC) by the expression of MRP L44 (MRPL44) messenger RNA (mRNA), and to investigate the clinicopathological features. GSEA clearly showed that the expression of OxPhos and MRP gene sets was significantly lower in primary thyroid cancer than in matched normal thyroid tissue. However, 8 of 49 primary thyroid tumors (16.3%) in the public repository did not show a reduction in OxPhos mRNA expression. Remarkably, strong positive correlations between MRPL44 expression and those of OxPhos and MRPs such as reduced nicotinamide adenine dinucleotide dehydrogenase (ubiquinone) 1 α subcomplex, 5; succinate dehydrogenase complex, subunit D; cytochrome c, somatic; adenosine triphosphate synthase, H+ transporting, mitochondrial Fo complex, subunit C1 (subunit 9); and MRP S5 (MRPS5) (P < 0.0001) were clearly denoted, suggesting that MRPL44 is a representative marker of OxPhos and MRP expressions. In laboratory experiments, metabolic heterogeneity in oxygen consumption, extracellular acidification rates (ECARs), and amounts of OxPhos complexes were consistently observed in BCPAP, TPC1, HTH-7, and XTC.UC1 cell lines. In PTCs, metabolic phenotype according to OxPhos amount defined by expression of MRPL44 mRNA was significantly related to lymph node metastasis (LNM) (P < 0.001). Furthermore, multivariate analysis clearly indicated that expression of MRPL44 is associated with an increased risk of lateral neck LNM (odds ratio 9.267, 95% confidence interval 1.852-46.371, P = 0.007). MRPL44 expression may be a representative marker of metabolic phenotype according to OxPhos amount and a useful predictor of LNM.

Utility of immunohistochemical markers in diagnosis of follicular cell derived thyroid lesions

Differentiating the follicular derived lesions can be challenging. Although immunohistochemistry is generally accepted as a useful ancillary technique in the diagnosis, controversy exists regarding the best marker or combination of markers to distinguish each lesion from its mimics. In this study, we aimed at evaluating multiple markers to compare their sensitivity and usefulness, and to find out if a combination of the evaluated markers can be of additional value in discriminating thyroid lesions. The study included two groups of follicular derived thyroid lesions; benign group (Grave's disease, nodular goiter, Hashimoto's and adenoma) and malignant group (papillary, follicular carcinoma, well differentiated tumors of unknown malignant potential and follicular tumour of unknown malignant potential). Immunohistochemical evaluation of CD56, HBME-1, Gaectin-3 and CK19 were done. The sensitivity, specificity for each marker and their combination were calculated. Each marker was sensitive and specific for certain lesion but the sensitivity and specificity was increased when use combination of markers. Although no single marker is completely sensitive and specific for follicular thyroid lesions, the combination of CD56, HBME-1, Gaectin-3 and CK19 attains high sensitivity and specificity in diagnosis.

HBME-1 expression in hyalinizing trabecular tumours of the thyroid gland

AIMS

Hyalinizing trabecular tumour (HTT) is a rare thyroid neoplasm with a trabecular growth pattern, marked intratrabecular hyalinization and nuclear features of papillary thyroid carcinoma (PTC). Immunohistochemical HBME-1 expression was reported recently in PTC, but not in HTT. To clarify further the value of HBME-1 expression as a tool in differential diagnosis, we investigated the immunophenotype of HTT.

METHODS AND RESULTS

Eight HTT diagnosed from 1997 to 2012 were reviewed on H&E-stained tissue sections and analysed for HBME-1, galectin-3, CK19 and Ki67 expression by immunohistochemistry. Three of eight HTTs (37.5%) were HBME-1 positive, with staining of tumour cells as well as of intratrabecular hyaline matrix material. All cases were CK19 negative. Galectin-3 was expressed weakly in four of eight cases (50%). Five of eight cases (62.5%) showed weak-to-moderate cytoplasmic Ki67 positivity.

CONCLUSIONS

Immunohistochemical HBME-1 expression is present in HTT and may not serve as a reliable marker in differentiating HTT from PTC. The HBME-1 positivity of the hyaline matrix suggests that this material is partly of cytoplasmic origin.

What are the keys to successful thyroid FNA interpretation?

There is much concern expressed in the literature regarding the lack of predictive power of the thyroid fine needle aspiration/biopsy (TFNAB) approach to defining the nature of clinically detected thyroid nodules. This has been exacerbated in the past decade or more by the routine use of ultrasonography (US) in examining the thyroid as well as the introduction of molecular testing in the realm of thyroid pathology. Some have even gone so far as to suggest replacing the TFNAB with molecular signature testing to reduce the degree of uncertainty for a specific cytological diagnosis. This review addresses those concerns with a re-emphasis on understanding the basic keys to successfully evaluating a patient with a thyroid nodule by routine TFNAB examination. These keys include bringing to bear an experienced group of physicians in an integrated team approach, a sharpened focus on the TFNAB cytological categories and a grounded understanding of the predictive ability of molecular testing in a given patient when the cytological interpretation creates too much uncertainty in the minds of the patients and clinicians in attempting to reach a decision on how to manage a thyroid nodule. With this practical approach in mind, the false-negative and false-positive rates of "negative (benign)" and "positive (malignant)" thyroid aspirates should be no more than 1%; and the prevalence of an "indeterminate" aspirate - the area in TFNAB attracting the most attention for improvement with novel biomarkers - should be 10% or less. Thus, physicians should be capable of managing at least 90% of patients undergoing TFNAB in a confident manner without further testing beyond the routine, future re-examination of the patient's nodule to re-assess for any change in its nature or its impact on the patient's quality of life. The other 10% can then be considered for molecular testing in a manner tailored to those individuals truly in need of a more sophisticated - and expensive - approach to the characterization of their thyroid nodules. As the era of US has matured - just as with the era of serum PSA testing for prostate cancer in men - we have experienced a paradigm shift: Given the incidence of thyroid nodules in the U.S. adult population in comparison with the risk of dying of thyroid malignancy, the main role of TFNAB is to reduce the need for surgical intervention.

Use of molecular markers in samples obtained from preoperative aspiration of thyroid

Several experiments have been carried out in order to find molecular markers that increase the diagnose accuracy of the Fine-Needle Aspiration (FNA), especially for thyroid lesions of undetermined significance. The growing number of published experiments on one or more of the different types of markers has started to justify the need to gather the pieces of information as a way to add evidence and guide the development of future research in the area. From the search arguments and criteria previously defined, 95 articles were selected from the electronic databases PUBMED, MEDLINE, SCOPUS and LILACS. From the 36 markers submitted to analysis and identified in preoperative FNA thyroid samples, only 10 (GAL3, CK-19, HBME-1, TPO, CD44, Telomerase, DAP IV, RAS, RET and BRAF) were assessed in more than two investigations, be it either in panel or individually. The minimum, medium and maximum values of sensibility, specificity, positive predictive value, negative predictive value and diagnose accuracy were obtained from the group of investigation, as well as the limitations and advantages of the use of each marker were identified. The BRAF mutation, for its unquestionable specificity, and the GAL3, for its regularity of average results obtained here, found in several locations in the cell as well as out of the cell, suggesting multiple functions of this molecule, were observed as holders of more expressive evidence in the effort of reducing the uncertainty of the diagnose in preoperative FNA of thyroid.

Diagnostic utility of immunohistochemical panel in various thyroid pathologies

BACKGROUND

For management of thyroid nodules, distinction between benign and malignant tumours is essential. The study was performed to evaluate the diagnostic value of molecular markers in different thyroid tumours.

MATERIALS AND METHODS

Immunohistochemistry for CD56, HBME-1, COX-2, Ki-67, p53 and E-cadherin (E-CAD) was performed in 113 benign and 35 malignant thyroid lesions including 36 follicular adenomas (FA), 77 colloid goitres, 26 papillary thyroid carcinomas (PTC) and 9 follicular carcinomas (FC). The results were scored semiquantitatively by staining intensity (0-3 scale) and percentage of positive cells.

RESULTS

PTC was characterised by decreased E-CAD and CD56 expression in contrast to surrounding benign thyroid tissues. HBME-1 expression was absent in benign thyroid tissues but was notably high in PTC and occasionally in FC. The expression of E-CAD and CD56 in FA was significantly higher than in the surrounding thyroid tissues. No expression of p53 was found in any group. The expression of COX-2 was low in all lesions. The proliferation activity by Ki-67 was generally low; however, it was significantly higher in cancers.

CONCLUSIONS

The panel consisting of three markers, HBME-1, E-CAD and CD56, can be recommended as an adjunct to morphology criteria. HBME-1 is found in malignant lesions only and is the most sensitive and specific single marker in PTC. Decreased expression of E-CAD and CD56 distinguishes PTC from FA and FC. Both FA and FC are characterised by high expression of E-CAD and CD56. The practical use of Ki-67 is difficult due to low values. The role of adhesion factors in thyroid malignancies may be superior in comparison with cell proliferation.

CXC chemokine receptor 4 immunodetection in the follicular variant of papillary thyroid carcinoma: comparison to galectin-3 and hector battifora mesothelial cell-1

BACKGROUND

The cytological discrimination between benign and malignant follicular-patterned lesions of the thyroid can represent a diagnostic challenge, even for experienced pathologists. We evaluated the diagnostic use of protein expression of CXC chemokine receptor 4 (CXCR4) and galectin-3 (gal-3) that were found to be upregulated in papillary thyroid carcinoma compared to normal thyroid and of mesothelial cell surface protein recognized by monoclonal antibody Hector Battifora Mesothelial cell (HBME)-1 in thyroid tumors.

METHODS

Expression of CXCR4, HBME-1, and gal-3 was examined immunohistochemically in total of 100 aspirates of thyroid lesions, categorized as benign (n = 22), indeterminate lesion (n = 43), suspicious of papillary thyroid carcinoma (n = 10), or malignant (n = 25) by preoperative cytology.

RESULTS

Expression of each individual marker was significantly associated with malignancy (p < 0.0001), although the sensitivity of detection ranged from 56% for gal-3 to 94% for HBME-1. When focusing on the indeterminate lesions, only CXCR4 and HBME-1 expression was associated with malignancy; moreover, these two markers either used individually or in combination showed good values of diagnostic accuracy (88.4% and 90.7%, respectively). Further, the combination of CXCR4 plus HBME-1 or the simultaneous use of all the three markers provided absolute value of sensitivity and negative predictive value in the same group of lesions.

CONCLUSIONS

An immunohistochemical panel, including CXCR4, could be useful in the differential diagnosis between benign and malignant well-differentiated follicular-patterned thyroid lesions.

A morpho-molecular diagnosis of papillary thyroid carcinoma: BRAF V600E detection as an important tool in preoperative evaluation of fine-needle aspirates

BACKGROUND

Although most thyroid nodule fine-needle aspiration (FNA) diagnoses are definitive or nearly definitive, about 30% of them are not read as definitively benign or malignant, the so-called indeterminate or suspicious FNA diagnosis. The prevalence of malignancy in FNA samples with these diagnoses varies from 10% to 52%. The first aim of this study was to determine if BRAF V600E analysis of thyroid FNA cytological smears could be performed with a relatively simple protocol. We also sought to determine if assessing the presence of BRAF gene mutations in preoperative FNA cytology slides would provide diagnostic information for FNA samples with a reading of indeterminate or suspicious thyroid lesions.

METHODS

DNA was extracted directly from FNA-stained smears of 111 patients with thyroid lesions having different cytological diagnoses. There was 1 cystic nodule, 20 microfollicular proliferations without atypia, 32 that were suspicious for papillary carcinoma, 56 papillary thyroid carcinomas (PTC), and 2 poorly differentiated carcinomas. The BRAF V600E mutational status was determined by sequencing analysis in all patients. The histopathological diagnosis was obtained in all cases.

RESULTS

We observed that 56/90 (62.3%) patients received a definitive diagnosis of PTC when only cytology was used. After molecular analysis, the BRAF V600E mutation was detected in 18/32 (56.2%) cases with a cytology of suspicious for papillary carcinoma and 41/56 (73.2%) with PTC. According to the morpho-molecular analysis (i.e., traditional cytology combined with BRAF V600E analysis) 74/90 (82.2%) patients could be assigned a definitive diagnosis of PTC. Therefore, the addition of molecular analysis yielded an increase of 20% in the sensitivity compared to cytology alone.

CONCLUSIONS

The method of molecular analysis of thyroid FNA smears described here can be easily performed after the FNA, thereby avoiding inconvenience and additional time during the FNA and permitting later analysis of samples having indeterminate cytology features. The increased sensitivity of this preoperative morpho-molecular analysis should provide information that is useful in deciding the extent of thyroid surgery for thyroid nodules that are indeterminate or suspicious on cytology.

Utility of malignancy markers in fine-needle aspiration cytology of thyroid nodules: comparison of Hector Battifora mesothelial antigen-1, thyroid peroxidase and dipeptidyl aminopeptidase IV

The purpose of this study was to compare the diagnostic interest of Hector Battifora mesothelial antigen-1 (HBME-1), thyroid peroxidase (TPO), and dipeptidyl aminopeptidase IV (DPP4) in thyroid fine-needle aspirates obtained from 200 resected thyroid lesions (55 colloid nodules, 54 follicular adenomas, 59 papillary cancers, and 32 follicular carcinomas). Hector Battifora mesothelial antigen-1 or TPO expression (% positive cells) and DPP4 staining score (12-point scale) were evaluated. Receiver operating characteristic (ROC) curves were plotted and optimal cutoff values for diagnosing malignancy were determined. The TPO ROC curve was consistently higher than the HBME-1 ROC curve. The TPO curve was also higher than the DPP4 curve with regard to sensitivity, but dipped below the DPP4 curve with regard to specificity. Using a cutoff value of <80% positive cells for TPO, >10% positive cells for HBME-1, and staining score > or =1 for DPP4, sensitivity to specificity ratios were 98-83% for TPO, 90-60% for HBME-1, and 88-80% for DPP4. Two particularly interesting findings of this study were the low negative likelihood ratio of TPO (0.02) allowing highly reliable exclusion of malignancy and the 100% specificity of DPP4 staining scores=12. Due to poor performance on follicular lesions, HBME-1 showed no advantage over TPO or DPP4.

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.

Immunohistochemistry differentiates papillary thyroid carcinoma arising in ectopic thyroid tissue from secondary lymph node metastases

OBJECTIVE

To verify whether immunohistochemistry might be useful in the distinction between a true laterocervical metastasis of an undetected thyroid carcinoma and a primary tumor outside the gland.

DESIGN

Galectin-3, cytokeratin 19, and HBME-1 were assessed in six cases (group A) of laterocervical masses harboring papillary thyroid carcinoma (PTC) but without a thyroid tumor, and in eight cases (group B) showing PTC both in the thyroid and in the laterocervical masses. In both groups, normal-looking follicles adjacent to the laterocervical neoplasia were present.

MAIN OUTCOME

We found that the apparently normal follicles in group A were negative for all the antibodies, while group B showed strong and diffuse positive immunostaining. The neoplastic areas were always positive for all the antibodies in both groups.

CONCLUSION

Even if immunohistochemical patterns of residual follicles of group B are very well differentiated that they resemble normal thyroid parenchyma, they may well be metastatic carcinomas. On the contrary, the presence of morphologically and immunohistochemically normal-looking follicles in group A, with no intrathyroid tumor, suggests that the primary PTC might possibly develop in the ectopic thyroid tissue. In cases showing morphologically and immunohistochemically normal-looking follicles in laterocervical masses, these findings might lead to a reduction of the overdiagnosis of metastatic disease of an undetected carcinoma.

Galectin-3 is highly expressed in nonencapsulated papillary thyroid carcinoma but weakly expressed in encapsulated type; comparison with Hector Battifora mesothelial cell 1 immunoreactivity

The histologic diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) may be troublesome, especially in its encapsulated form. We evaluated the expression of galectin-3 (gal-3) and Hector Battifora mesothelial cell (HBME-1) in 200 formalin-fixed thyroid tissues with diagnosis of classical variant of papillary thyroid carcinoma or FVPTC, encapsulated or with infiltrative growth, with or without lymph node metastasis. All cases of classical variant of papillary thyroid carcinoma were consistently positive for gal-3; similar results have been obtained by using HBME-1. Interestingly, the invasive type of FVPTC, with or without metastasis, was strongly positive for gal-3 (78.2% and 96%, respectively), whereas only 46.8% of encapsulated FVPTCs without metastasis showed immunostaining for this marker. In the latter group, the HBME-1 expression achieved a significantly higher percentage of positivity (87%). Surprisingly, gal-3 immunodetection showed negative results in 4 encapsulated FVPTCs, despite the strong immunoreactivity in corresponding metastasis. Our data suggest that gal-3 immunodetection alone is not able to support the diagnosis of encapsulated FVPTCs.

Current status of fine needle aspiration for thyroid nodules

When not to perform fine needle aspiration of a thyroid nodule In summary, FNA of thyroid nodules has become one of the most useful, safe, and accurate tools in the diagnosis of thyroid pathology. Thyroid nodules that should be considered for FNA include any firm, palpable, solitary nodule or nodule associated with worrisome clinical features (rapid growth, attachment to adjacent tissues, new hoarseness, or palpable lymphadenopathy). FNA should also be performed on nodules with suspicious ultrasonographic features (microcalcifications, rounded shape, predominantly solid composition); dominant or atypical nodules in multinodular goiter; complex or recurrent cystic nodules; or any nodule associated with palpable or ultrasonographically abnormal cervical lymph nodes. Finally, FNA should be performed on any abnormal-appearing or palpable cervical lymph nodes. The management of thyroid nodules based on FNA findings is summarized in Table 2. It can be argued that in certain circumstances the results of thyroid FNA do not change the surgical management of a thyroid nodule, and thus preoperative FNA may be unnecessary. These cases include solitary nodules in patients who have a strong family history of thyroid cancer, multiple endocrine neoplasia type II, or radiation to the head and neck. These patients when they have thyroid nodules have at least a 40% risk for thyroid cancer and frequent multifocal or bilateral disease and should undergo total thyroidectomy with or without central neck lymph node dissection. Patients who have multinodular goiter and compressive symptoms, patients who have Graves disease and a thyroid nodule, or patients who have large (greater than 4 cm) or symptomatic unilateral thyroid nodules could also be considered for total thyroidectomy or lobectomy as indicated without preoperative FNA. Finally, patients who have a solitary hyperfunctioning nodule on radioiodine scan and a suppressed TSH have an extremely low incidence of malignancy and may be considered for therapeutic thyroid lobectomy or radioiodine ablation as indicated without undergoing FNA biopsy.

Microarray analysis of thyroid nodule fine-needle aspirates accurately classifies benign and malignant lesions

Current preoperative diagnostic procedures for thyroid nodules rely mainly on the cytological interpretation of fine-needle aspirates (FNAs). DNA microarray analysis has been shown to reliably distinguish benign and malignant thyroid nodules in surgically resected specimens, but its diagnostic potential in thyroid FNA has not been examined. In the present study, the expression profiles of 50 benign thyroid lesions and papillary thyroid carcinoma tissue samples were compared, generating a list of 25 differentially expressed genes from this training set. A test set of 22 FNA specimens was evaluated by unsupervised hierarchical cluster analysis using this gene list, and the results were compared to FNA cytology. FNA specimens were found to fall into three clusters: malignant (n = 10), benign (n = 7), and indeterminate (n = 5). The benign and malignant groups showed complete concordance with the final histological diagnosis except for one histologically benign lesion, which was rediagnosed as follicular variant of papillary thyroid carcinoma on histological review. Paired analysis between FNA and matched tissues samples illustrated adequate sampling with FNA. These results illustrate that microarray analysis of FNA is feasible and has the potential to improve the accuracy of FNA in categorizing benign from malignant lesions beyond routine cytological evaluation.

Simultaneous immunohistochemical expression of HBME-1 and galectin-3 differentiates papillary carcinomas from hyperfunctioning lesions of the thyroid

AIMS

The histological diagnosis is critical for the postsurgical management and follow-up of thyroid malignancies. The differential diagnosis between papillary carcinoma and hyperfunctioning lesions, either with papillary hyperplasia or with a follicular architecture, can create real diagnostic difficulty. The aim of this study was to evaluate the expression of several antibodies considered to be markers of malignancy in malignant and hyperfunctioning thyroid neoplasms and to include the most effective of them in a diagnostic panel.

METHODS AND RESULTS

One hundred resected thyroid nodules--58 hyperfunctioning benign lesions and 42 papillary carcinomas (14 follicular variant, 14 macrofollicular variant and 14 classic type)--were immunohistochemically studied for HBME-1, galectin-3, cytokeratin (CK) 19 and RET-proto-oncogene. HBME-1 and galectin-3 showed 92.8% and 89% sensitivity, respectively, and their coexpression was present in 36 out of 42 papillary carcinomas (85.7%) and absent in non-malignant lesions. Their association increased sensitivity to 94.7% and the diagnostic accuracy to 97.9% and involved the highest number of cases (95%) in comparison with two other panels including, respectively, three (HBME-1, galectin-3, CK19) and all four antibodies.

CONCLUSION

An immunohistochemical panel consisting of HBME-1 and galectin-3 can make a correct distinction between malignant and hyperfunctioning thyroid neoplasms with high diagnostic accuracy.

Utility of BRAF V600E mutation detection in cytologically indeterminate thyroid nodules

Background

Fine needle aspiration (FNA) is widely utilized for evaluation of patients with thyroid nodules. However, approximately 30% are indeterminate for malignancy. Recently, a mutation in the BRAF gene has been reported to be the most common genetic event in papillary thyroid carcinoma (PTC). In this retrospective study, we assessed the utility of BRAF V600E mutation detection for refining indeterminate preoperative cytologic diagnoses in patients with PTC.

Methods

Archival indeterminate thyroid FNAs and corresponding formalin-fixed, paraffin-embedded (FFPE) surgical samples with PTC were identified in our patient files. DNA extracted from slide scape lysates and 5 μm FFPE sections were evaluated for the BRAF V600E mutation using LightCycler PCR and fluorescent melting curve analysis (LCPCR). Amplification products that showed deviation from the wild-type genomic DNA melting peak, discordant FNA and FFPE matched pairs, and all benign control samples, underwent direct DNA sequencing.

Results

A total of 19 indeterminate thyroid FNAs demonstrating PTC on FFPE surgical samples were included in the study. Using BRAF mutation analysis, the preoperative diagnosis of PTC was confirmed in 3/19 (15.8%) FNA samples that could not be conclusively diagnosed on cytology alone. However, 9/19 (47.4%) FFPE tissue samples were positive for the V600E mutation. Of the discordant pairs, 5/6 FNAs contained less than 50% tumor cells.

Conclusion

When used with indeterminate FNA samples, BRAF mutation analysis may be a useful adjunct technique for confirming the diagnosis of malignancy in an otherwise equivocal case. However, overall tumor cell content of some archival FNA smear slides is a limiting factor for mutation detection.

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.

Immunohistochemical separation of follicular variant of papillary thyroid carcinoma from follicular adenoma

The accurate diagnosis of differentiated thyroid tumors is very important for clinical management of patients. The histopathological distinction between some types of differentiated thyroid tumors can be very difficult even for experienced pathologists. We used immunohistochemical markers from published data obtained from DNA expression profiling, tissue microarray analysis, and immunohistochemistry to analyze a series of 157 thyroid tumors and 5 normal thyroids. These analyses showed that several antibodies were useful in distinguishing follicular adenomas from follicular variant of papillary thyroid carcinomas including HBME-1, CITED1, galectin-3, cytokeratin 19, and S100A4 (p < 0.0001). A combination of markers consisting of a panel of HBME-1, galectin-3, and CK19 or a panel of HBME-1, CITED1, and galectin-3 was usually most effective in distinguishing follicular adenoma from follicular variant of papillary thyroid carcinoma. Because individual tumors may not express some of these markers, the use of a panel of antibodies is recommended. These results indicate that some individual antibodies or a panel of antibodies combined with histopathological analysis can be useful in separating follicular adenoma (FA) from follicular variant of papillary thyroid carcinoma (FVPTC).

The many faces and mimics of papillary thyroid carcinoma

This article provides an overview of the 15 histologic variants of papillary thyroid carcinoma listed by the 2004 World Health Organization (WHO) monograph on endocrine tumors. The histologic features, differential diagnosis, and clinical course of each variant are discussed in some detail. The follicular variants (conventional and macrofollicular) constitute a morphologic challenge because the majority of these tumors are encapsulated and, also, because, in many tumors, not all neoplastic cells show the nuclear features considered to be diagnostic of papillary carcinoma. As a result, most of these tumors are missed even by experienced pathologists. Moreover, hyperplastic thyroid lesions, follicular adenomas, and Hashimoto's thyroiditis may contain cells with clear nuclei resembling those of papillary carcinoma. Papillary carcinomas composed entirely of hyperchromatic cells have been overlooked. The WHO monograph defines papillary carcinoma with focal spindle and giant cell carcinoma components but its clinical behavior is unknown. Papillary carcinoma with an insular pattern that does not show the artifactual separation of the cell nests has been misinterpreted as the solid variant of papillary carcinoma. Papillary microcarcinomas include not only the conventional type and the follicular variants but also the tall cell and columnar cell variants.

Usefulness of HBME-1, cytokeratin 19 and galectin-3 immunostaining in the diagnosis of thyroid malignancy

AIMS

To investigate the usefulness of immunohistochemical expression and immunolocalization of a panel of thyroid malignancy markers including HBME-1, cytokeratin (CK) 19 and galectin-3.

METHODS AND RESULTS

We evaluated 170 thyroid lesions including 148 neoplastic lesions [84 papillary carcinomas (PC), 38 follicular carcinomas (FC), 18 follicular adenomas, one hyalinizing trabecular tumour, five medullary carcinomas, two anaplastic carcinomas] and 22 non-neoplastic lesions (12 adenomatous nodules and 10 Hashimoto's thyroiditis). HBME-1, galectin-3 and CK 19 were expressed in 94%, 72.6%, 72.6% of PCs and in 63%, 21%, 21% of FCs. The three markers were mostly negative in all normal tissues. Although the most helpful marker in terms of sensitivity and specificity for the follicular variant of PC and for FC diagnosis was HBME-1, when we consider the differentiation between cases of follicular variant of papillary carcinoma (FVPC) and FC or adenoma, in terms of percentage of positive cells, galectin-3 and CK 19 were more relevant.

CONCLUSIONS

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.

From the bench to the bedside. Galectin-3 immunodetection for improving the preoperative diagnosis of the follicular thyroid nodules

The authors discuss the principal aspects concerning the preoperative characterization of thyroid nodules, in particular those with follicular histology, and illustrate the potential clinical impact of a new diagnostic test-method, named "galectin-3 thyrotest", which is based on the immunodetection of galectin-3 molecule in cytological specimens derived from thyroid nodular lesions. This diagnostic test method, which consistently improves the accuracy of conventional cytology, has been recently validated in a large international multicenter study and is going to impact hardly the clinical management of patients bearing thyroid nodular diseases. The rationale of this new diagnostic approach, the possibility to improve its performance in selected cases by using large needle aspiration biopsy (LNAB) together with technical and operative details are presented and discussed.

The role of immunohistochemical markers in the diagnosis of follicular-patterned lesions of the thyroid

Thyroid nodules are extremely common in the general population. The differential diagnosis includes numerous entities, non-neoplastic and neoplastic, benign and malignant. However, the diagnosis of follicular-patterned lesions remains an area fraught with controversy and diagnostic criteria are highly variable. It is, therefore, a field in need of objective, scientific markers that better characterize these lesions than has been possible by classical morphology. A number of candidates have been proposed. No single marker can identify all malignant follicular-patterned lesions, however, various combinations have been proposed. They include HBME-1, high molecular weight cytokeratins and ret, galectin-3 and TPO, galectin-3, fibronectin-1, CITED-1, HBME-1, and CK19. Advances in our understanding of the molecular basis of thyroid cancer will allow the identification of new markers and more accurate characterization of specific subtypes of neoplasia and malignancy. As new markers are characterized and validated, directed by molecular profiling of thyroid lesions with characteristic morphology, behavior, and outcome, they will become available as routine immunohistochemical markers that will provide a more accurate, scientific, and clinically relevant consultation report from the pathologist for cytology and surgical pathology procedures. Application of these markers will enhance the diagnosis of thyroid nodules and better guide the management of patients with these lesions.

Detection and molecular characterisation of thyroid cancer precursor lesions in a specific subset of Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) represents the most common cause of hypothyroidism and nonendemic goiter, but its clinical and pathological heterogeneity opens the question if this disease should be more properly considered as a spectrum of different thyroid conditions rather than as a single nosological entity. In this study, we analysed 133 cases of HT for the expression of galectin-3, a lectin molecule involved in malignant transformation, apoptosis and cell cycle control. An unexpected expression of galectin-3 was demonstrated in a subset of HT together with the presence of HBME-1, c-met and cyclin-D1 that are also involved in malignant transformation and deregulated cell growth. Furthermore, a loss of allelic heterozygosity in a specific cancer-related chromosomal region was demonstrated in some HT harbouring galectin-3-positive follicular cells, by using laser capture microdissection. On the basis of the morphological and molecular findings we identified four subsets of HT: (a) HT with classic features of chronic autoimmune thyroiditis; (b) HT associated to hyperplastic/adenomatous lesions; (c) HT harbouring thyroid cancer precursors; (d) HT associated to unequivocal thyroid microcarcinomas. Our findings provide a well-substantiated morphological and molecular demonstration that HT may include a spectrum of different thyroid conditions ranging from chronic autoimmune thyroiditis to thyroiditis triggered by specific immune-response to cancer-related antigens.

Distinction between papillary thyroid hyperplasia and papillary thyroid carcinoma by immunohistochemical staining for cytokeratin 19, galectin-3, and HBME-1

The histopathology of papillary thyroid hyperplasia and papillary thyroid carcinoma is similar enough to cause a diagnostic dilemma in a few cases. Both lesions may have papillary fronds with fibrovascular cores, nuclear crowding, and nuclear anisocytosis. Formalin- fixed paraffin-embedded tissues from 30 randomly selected patients with papillary thyroid hyperplasia and an equal number from patients with papillary thyroid carcinoma were analyzed for expression of cytokeratin 19 (CK19), galectin-3, and HBME-1. Cases of papillary thyroid carcinoma had moderate to strong CK19, galectin-3, and HBME-1 reactivity although both CK19 and galectin-3 showed positive staining in a significant number of nonneoplastic thyroid cases. HBME-1 was uncommon in the nonneoplastic cases. These results indicate that HBME-1 may be useful in helping to distinguish papillary thyroid carcinoma from hyperplasia in diagnostically difficult cases.

Hybrid thyroid carcinoma with a coarse chromatin pattern and nuclear features of papillary thyroid carcinoma

Hybrid follicular carcinoma (FC) and papillary thyroid carcinoma (PTC) have not been previously well described. Consecutive cases of 29 FC, 12 Hurthle cell carcinomas (HC), 247 PTC and 13 Hurthle cell PTC (HPTC) were reviewed with special attention to the coarse (CC) and fine chromatin patterns (FIC), as well as to the presence of nuclear grooves, pseudoinclusions or optically clear appearance. Limited nuclear features of PTC (LNF-PTC) are defined as areas of tumor with FIC in addition to some other nuclear features, but insufficient for the diagnosis of PTC. Tumors with nuclei showing an admixture of CC and PTC or LNFPTC were submitted for immunostaining for cytokeratin 19, HBME and Ret/PTC. FC and HC contained areas of LNFPTC in 25 tumors and focal PTC in 3 tumors. None of these cases was associated with lymph node metastasis. Areas with CC were found in 54 PTC and 3 HPTC. The rates of vascular invasion and distant metastasis tended to be higher for PTC with areas of coarse chromatin pattern than for PTC without such areas; however, the difference was not statistically significant. Immunoreactivity for cytokeratin 19 and HBME was moderate to strong for PTC and focal areas of PTC or LNFPTC in FC without Hurthle cell changes. Ret/PTC immunostaining was positive in areas of LNFPTC or focal PTC in three FC. Focal PTC or areas of LNFPTC are frequently seen in FC. Likewise, areas of CC are often present in PTC. The presence of these focal areas does not appear to change the clinical behavior of the tumor and therefore does not warrant a change of nomenclature.

The meanings of markers: ancillary techniques in diagnosis of thyroid neoplasia

This review article primarily discusses immunohistochemical markers used to aid the diagnosis of thyroid neoplasia. The review concentrates on high molecular weight cytokeratins, cytokertain 19, HBME-1, and galectin-3. Diagnostic uses of proliferation markers such as p27(kip1) and Ki-67 are discussed along with the oncogene ret in relation to papillary carcinomas and PAX8-peroxisome proliferator-activated receptor gamma1 in relation to follicular carcinoma. The diagnostic use of retinoblastoma tumor suppressor gene product is also discussed. The sensitivities and specificities as well as the pitfalls of these techniques are reviewed. On the basis of the literature, the most highly recommended of these markers to aid in diagnosis are HBME-1 and galectin-3.

Molecular diagnostic tests in the diagnosis and management of thyroid carcinoma

The application of molecular analysis of gene expression to clinical tissue samples represents one of the most exciting new areas in "translational" thyroid cancer research. Current data suggest that molecular diagnostic assays may improve the sensitivity and accuracy of fine needle aspiration of thyroid nodules, fine needle aspiration of metastases, and detection of recurrent disease in peripheral blood samples. It is likely that at least some of these tests will become useful adjuncts in the diagnostic armamentarium of clinical endocrinologists in the future.

Phage-display library selection of high-affinity human single-chain antibodies to tumor-associated carbohydrate antigens sialyl Lewisx and Lewisx

mAbs against tumor-associated carbohydrate antigens have the potential to play a prominent role in cancer immunotherapy. However, it has not been possible to fully exploit the clinical utility of such antibodies primarily, because those of adequate affinity could be derived only from murine sources. To address this problem, we prepared a single-chain Fv (scFv) antibody library from the peripheral blood lymphocytes of 20 patients with various cancer diseases. Completely human high-affinity scFv antibodies were then selected by using synthetic sialyl Lewisx and Lewisx BSA conjugates. These human scFv antibodies were specific for sialyl Lewisx and Lewisx, as demonstrated by ELISA, BIAcore, and flow cytometry binding to the cell surface of pancreatic adenocarcinoma cells. Nucleotide sequencing revealed that at least four unique scFv genes were obtained. The Kd values ranged from 1.1 to 6.2 x 10(-7) M that were comparable to the affinities of mAbs derived from the secondary immune response. These antibodies could be valuable reagents for probing the structure and function of carbohydrate antigens and in the treatment of human tumor diseases.