Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms

Clinical value of Cyclin D1 and P21 in the differential diagnosis of papillary thyroid carcinoma

BACKGROUND

With the continuous discovery of new borderline thyroid lesions and benign and malignant "gray areas", coupled with the limitations of traditional immune indicators, the differential diagnosis of papillary thyroid carcinoma (PTC) has become more difficult. Cyclin D1 and P21 are cell cycle regulators involved in the occurrence and metastasis of multiple tumors, including PTC, but their specific functions are unclear.

METHODS

In our study, immunohistochemical staining was used to explore the expression of Cyclin D1 and P21 in PTC, paracancerous tissue, follicular adenoma (FA) and papillary thyroid hyperplasia. In addition, their relationship with the clinicopathological features of PTC and their differential diagnostic value in distinguishing between intralymph node PTC metastases and intralymph node ectopic thyroid tissue were studied.

RESULTS

Among 200 primary PTC lesions, Cyclin D1 and P21 were found to be expressed in 186 (93.00%) and 177 (88.50%), respectively, and their expression levels were significantly higher in PTC tissue than in adjacent tissue, FA tissue and papillary thyroid hyperplasia tissue (P < 0.05). The expression levels of Cyclin D1 and P21 were positively correlated with tumor size and lymph node metastasis (P < 0.05) but not with sex, age, number of tumor lesions, histological subtype, chronic lymphocytic thyroiditis or TNM stage (P < 0.05). The expression levels of Cyclin D1 and P21 were significantly correlated (P < 0.05). The positivity rates of Cyclin D1 and P21 in intralymph node PTC metastases were 97.96% (48/49) and 89.80% (44/49), respectively, which were significantly higher than those in intralymph node ectopic thyroid tissue (P < 0.05). The sensitivity (Se) and negative predictive value (NPV) of Cyclin D1 and P21 detection alone or in combination were higher than those of the combined detection of the classical antibody markers CK19, HBME-1 and Galectin-3. Besides, the Se, Sp, PPV and NPV of Cyclin D1 and P21 in differentiating intralymph node PTC metastases and intralymph node ectopic thyroid tissue were higher.

CONCLUSIONS

The results of our study show that Cyclin D1 and P21 are highly sensitive and specific markers for the diagnosis of PTC that are superior to traditional classical antibodies. And, these two markers are of great value in the differential diagnosis of intralymph node PTC metastases and intralymph node ectopic thyroid tissue.

Immunomodulation exerted by galectins: a land of opportunity in rare cancers

Rare cancers represent only 5% of newly diagnosed malignancies. However, in some cases, they account for up to 50% of the deaths attributed to cancer in their corresponding organ. Part of the reason is that treatment options are generally quite limited, non-specific, and very often, only palliative. Needless to say, research for tailored treatments is warranted. Molecules that exert immunomodulation of the tumor microenvironment are attractive drug targets. One such group is galectins. Thus, in this review we summarize the current knowledge about galectin-mediated immunomodulation in rare cancers, highlighting the research opportunities in each case.

FAM172A promotes follicular thyroid carcinogenesis and may be a marker of FTC

Our aims were to uncover the role of FAM172A (Family with sequence similarity 172 member A) in the pathogenesis of follicular thyroid carcinoma (FTC) and to evaluate its value in the differential diagnosis between malignant and benign thyroid follicular lesions. FAM172A expression was evaluated by q-PCR, immunoblotting and immunohistochemistry (IHC). The ability of proliferation, migration and invasion of cells were assessed by Cell Counting Kit-8 assay (CCK8), clone-formation and Transwell assays. Nude mouse tumorigenicity assays were used to investigate the role of FAM172A in the pathogenesis of FTC in vivo. The value of FAM172A in the differential diagnosis for FTC was assessed using 120 formalin-fixed paraffin-embedded (FFPE) tissues after the operation and 81 fine-needle aspiration biopsy (FNAB) samples before the operation. FAM172A was highly expressed in FTC tissues and FTC cell lines. Downregulation of FAM172A inhibited the proliferation, invasion and migration of FTC cells through Erk1/2 and JNK pathways. Subcutaneous tumorigenesis in nude mice showed that knockdown of FAM172A inhibited tumor growth and progression in vivo. The FAM172A IHC scores of 3.5 had 92% sensitivity and 63% specificity to separate FTC from benign/borderline thyroid follicular lesions, and 92% sensitivity and 80% specificity to discriminate FTC from benign thyroid follicular lesions in postoperative FFPE samples. The corresponding values were 75 and 78%, and 75 and 89% in preoperative FNA samples, respectively. FAM172A plays an important role in the pathogenesis of FTC through Erk1/2 and JNK pathways. FAM172A may be a potential marker for the preoperative diagnosis of FTC based on the IHC results of thyroid FNAB samples.

Role of CD10 Marker in Differentiating Malignant Thyroid Neoplasms from Benign Thyroid Lesions (Immunohistochemical & Histopathological Study)

BACKGROUND:

CD10 was initially recognised as a cell–surface antigen expressed by acute lymphoblastic leukaemias, and hence it’s early designation as Common Acute Lymphoblastic Leukemia Antigen (CALLA). Also, it has been proven to be reactive in various non-lymphoid cells and tissue and different types of neoplasms.

AIM:

To evaluate the immunohistochemical expression of CD10 in malignant thyroid neoplasms and different benign lesions and to assess whether CD10 can be used as a malignancy marker in thyroid pathology or not.

MATERIAL AND METHODS:

A total of 83 archived, formalin fixed, paraffin embedded tissue blocks of 83 cases of malignant thyroid neoplasms and different benign lesions. The samples were immunohistochemically analysed for CD10 expression. A p-value of less than 0.05 was considered statistically significant.

RESULTS:

CD10 was expressed in 91% of the studied malignant thyroid neoplasms and 58% of benign thyroid lesions. It was expressed in 26 of 28 (92.9%) conventional papillary carcinomas, ten of 10 (100%) follicular variants of papillary carcinoma, seven of nine (77.8%) minimally invasive follicular carcinomas, two of three (66.7%) widely invasive follicular carcinomas, and seven of 7 (100%) undifferentiated carcinomas, seven of 11 (66.7%) adenomatous nodules and eight of 15 (53.3%) follicular adenomas. No statistically significant correlations were detected between CD10 expression and patients’ age, sex, lymph node metastasis, tumour stage and capsular invasion.

CONCLUSION:

CD10 shows strong sensitivity (91.2%) and moderate specificity (42.3%) in the diagnosis of malignancy overall and shows strong sensitivity (86.4%) and moderate specificity (42.3%) in the diagnosis of malignancy in the follicular-patterned lesions. So, CD10 might be useful in differentiating malignant from benign thyroid lesions (good positive test) and in the diagnosis of follicular variant of papillary carcinoma.

Immunohistochemical Biomarkers in Thyroid Pathology

The application of immunohistochemistry to the diagnosis of thyroid lesions has increased as new biomarkers have emerged. In this review, we discuss the biomarkers that are critical for accurate diagnosis, prognosis, and management. Immunohistochemical markers are used to confirm that an unusual tumor in the thyroid is indeed of thyroid origin, either of follicular epithelial or C-cell differentiation; the various mimics include nonthyroidal lesions such as parathyroid tumors, paragangliomas, thymic neoplasms, and metastatic malignancies. Tumors of thyroid follicular epithelial cells can be further subclassified using a number of immunohistochemical biomarkers that can distinguish follicular-derived from C-cell lesions and others that support malignancy in borderline cases. The use of mutation-specific antibodies can distinguish papillary carcinomas harboring a BRAF^V600E mutation from RAS-like neoplasms. Immunostains have been developed to further identify molecular alterations underlying tumor development, including some rearrangements. Altered expression of several biomarkers that are known to be epigenetically modified in thyroid cancer can be used to assist in predicting more aggressive behavior such as a propensity to develop locoregional lymphatic spread. Immunohistochemistry can assist in identifying lymphatic and vascular invasion. Biomarkers can be applied to determine dedifferentiation and to further classify poorly differentiated and anaplastic carcinomas. The rare tumors associated with genetic predisposition to endocrine neoplasia can also be identified using some immunohistochemical stains. The application of these ancillary tools allows more accurate diagnosis and better understanding of pathogenesis while improving prediction and prognosis for patients with thyroid neoplasms.

Galectin-3 Performance in Histologic a Cytologic Assessment of Thyroid Nodules: A Systematic Review and Meta-Analysis

The literature on Galectin-3 (Gal-3) was systematically reviewed to achieve more robust information on its histologic reliability in identifying thyroid cancers and on the concordance between Gal-3 test in histologic and cytologic samples. A computer search of the PubMed and Scopus databases was conducted by combinations of the terms thyroid and Gal-3. Initially, 545 articles were found and, after their critical review, 52 original papers were finally included. They reported 8172 nodules with histologic evaluation of Gal-3, of which 358 with also preoperative FNAC Gal-3 assessment. At histology, Gal-3 sensitivity was 87% (95% confidence intervals [CI] from 86% to 88%), and specificity 87% (95% CI from 86% to 88%); in both cases, we found heterogeneity (I₂ 85% and 93%, respectively) and significant publication bias (p < 0.001). The pooled rate of positive Gal-3 at fine needle aspiration (FNAC) among cancers with histologically proven Gal-3 positivity was 94% (95% CI from 89% to 97%), with neither heterogeneity (I₂ 14.5%) nor bias (p = 0.086). These data show high reliability of Gal-3 for thyroid cancer at histology, while its sensitivity on FNAC samples is lower. The limits of cytologic preparations and interpretation of Gal-3 results have to be solved.

Combination of galectin-3, CK19 and HBME-1 immunostaining improves the diagnosis of thyroid cancer

Currently, fine-needle aspiration is the most frequently used pre-operative technique for diagnosis of malignant thyroid tumors, however, pathologists are unable to reach efficient and accurate differential diagnoses between benign and malignant thyroid nodules. To aid in resolving this issue, immunohistochemistry for galectins (gal)-1, −3, −7, −8, cytokeratin 19 (CK19), Hector Battifora Mesothelial Epitope-1 (HBME-1) and thyroid peroxidase (TPO) was performed on two tissue microarrays composed of 66 follicular adenomas (FA) and 66 papillary carcinomas (PC). The identification of optimal cut-off levels and the diagnostic value of single immunomarkers or combinations were evaluated using the receiver operating characteristic curve analysis. Signal intensities for gal-1, gal-3, CK19 and HBME-1 were significantly greater in PC compared with FA (P<0.001). Conversely, expression levels of TPO were significantly increased in FA compared with PC (P<0.001). Gal-3 and CK19 appeared to be the most sensitive markers (97 and 98%, respectively), whereas galectin-1 was the most specific (97%). The combination of gal-3, CK19 and HBME-1 acted as the most efficient and informative marker panel reaching the greatest specificity (97%) and sensitivity (95%) for the diagnosis of PCs. The findings suggest that this combination of markers may improve the reliability of diagnosis of thyroid cancer.

Galectin-1 is a diagnostic marker involved in thyroid cancer progression

Fine-needle aspiration (FNA) is the most commonly used pre-operative technique for diagnosis of malignant thyroid tumor. However, many benign lesions, with indeterminate diagnosis following FNA, are referred to surgery. Based on multifunctionality of the endogenous galectin-1, we aimed to assess its status for early diagnosis of thyroid cancer. Immunohistochemistry for galectin-1 and -3 was performed on a clinical series of 69 cases of thyroid lesions. Galectin-1 expression was further examined in two additional tissue microarrays (TMA) composed of 66 follicular adenomas and 66 papillary carcinomas in comparison to galectin-3 and cytokeratin-19 (CK19). In addition, a knockdown of galectin-1 in papillary (TPC-1) and anaplastic (8505C) thyroid cancer cell lines was achieved by lentiviral transduction for in vitro experiments. A murine orthotopic thyroid cancer model was used to investigate tumor growth and metastatic ability. Immunohistochemical analyses of galectin-1 and -3 in the series of 69 cases of thyroid lesions revealed that galectin-1 was completely absent in the epithelial compartment of all benign thyroid lesions. Levels of both galectins significantly increased in the cytoplasmic compartment of malignant thyroid cells. Galectin-1 expression in the TMA yielded an excellent specificity (97%), while galectin-3 and CK19 presented a higher sensitivity (>97%) in discriminating benign from malignant thyroid lesions. In vitro experiments revealed that migration was negatively affected in TPC-1 galectin-1 knockdown (KD) cells, and that proliferation and invasion capacity of 8505C cells decreased after galectin-1 KD. Moreover, an orthotopic mouse model displayed a lower rate of tumor development with galectin-1 KD thyroid anaplastic cancer cells than in the control. Our findings support the introduction of galectin-1 as a reliable diagnostic marker for thyroid carcinomas. Its involvement in cell proliferation, migration, invasion and tumor growth also intimate functional involvement of galectin-1 in the progression of thyroid carcinoma, suggesting its potential as a therapeutic target.

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.

Sensitivity and Specificity of Galectin-3 and Glypican-3 in Follicular-Patterned and Other Thyroid Neoplasms

INTRODUCTION

Diagnosing follicular-patterned thyroid neoplasm can be quiet challenging in some cases, where an immunohistochemical profiling becomes mandatory. Galectin-3 may be a helpful tool for classical PTC diagnosis, but it cannot be considered as a diagnostic marker of malignancy. Glypican-3, in contrast, is not thoroughly studied in thyroid neoplasms.

AIM

Determine the sensitivity and specificity of galectin-3 and glypican-3 in diagnosing thyroid carcinoma and follicular-patterned thyroid carcinoma.

MATERIALS AND METHODS

A retrospective study was conducted on archival blocks diagnosed from pathology department between 2010 and 2012 including 17 cases of follicular adenoma, 16 cases of Classic Papillary Thyroid Carcinoma (PTC), 6 cases of Follicular Variant of Papillary Thyroid Carcinoma (FVPTC), 3 cases of follicular carcinoma, 5 cases of medullary carcinoma and 1 case of Hürthle cell carcinoma. The nearby non neoplastic (normal) thyroid follicles present in both adenoma and carcinoma cases were also evaluated.

STUDY DESIGN

Evaluation of both galectin-3 and glypican-3 expression using standard immunohistochemical techniques.

STATISTICAL ANALYSIS USED

Descriptive analysis of the variables and statistical significances were calculated by non-parametric chi-square test using the Statistical Package for the Social Sciences version 12.0 (SPSS).

RESULTS

Five (30%) and 4 (24%) out of the 17 studied follicular adenoma cases, were positively stained by galectin-3 and glypican-3 respectively, while 30 (97%) and 25 (81%) cases out of the studied 31 carcinoma cases were positively stained by galectin-3 and glypican-3 respectively. The sensitivity, specificity and diagnostic accuracy of galectin-3 vs. glypican-3 in discrimination between thyroid carcinoma and adenoma was 96.8%, 70.6%, and 87.5%vs. 81% 76.5% and 79% respectively. As for the discrimination between follicular-patterned thyroid carcinoma and follicular adenoma it was 90%, 71% and 78% vs. 90% 76.5% and 82%.

CONCLUSION

Glypican-3 is more specific while galectin-3 is more sensitive in diagnosing thyroid carcinoma while glypican-3 is more specific than galectin-3 in discriminating follicular-patterned neoplasm.

Galectin-3 Is Elevated and Associated With Adverse Outcomes in Patients With Single-Ventricle Fontan Circulation

BACKGROUND

Galectin-3 may play a role in cardiac and noncardiac fibrosis, and elevated circulating levels of this protein predict adverse outcomes in patients with heart failure who do not have congenital heart disease. We investigated galectin-3 in adults with single-ventricle Fontan circulation, patients who are prone to premature clinical deterioration in the context of extensive multiorgan fibrosis.

METHODS AND RESULTS

We measured plasma galectin-3 concentrations in 70 ambulatory adult Fontan patients and 21 age- and sex-matched control participants. Galectin-3 level was significantly higher in the Fontan group (11.85 ng/mL, interquartile range 9.9 to 15.0 ng/mL) versus the control group (9.4 ng/mL, interquartile range 8.2 to 10.8 ng/mL; P<0.001). Among Fontan patients, galectin-3 was positively correlated with age, uric acid, and high-sensitivity C-reactive protein and negatively correlated with estimated glomerular filtration rate. There was no significant relationship between galectin-3 and oxygen saturation, Fontan type, or ventricular morphology. Over a median follow-up of 461 days, 15 events occurred among the Fontan patients: 12 nonelective hospitalizations (with 2 subsequent deaths) and 3 deaths without prior hospitalization. Patients with elevated galectin-3 (n=19, defined as >2 SD above the control group mean value) had a higher risk of nonelective hospitalization or death (hazard ratio 6.0, 95% CI 2.1 to 16.8, P<0.001). This relationship persisted after individual adjustment for covariates including age, New York Heart Association functional class, C-reactive protein, and estimated glomerular filtration rate and after multivariable adjustment for independently predictive covariates (hazard ratio 9.2, 95% CI 2.4 to 35.2, P=0.001).

CONCLUSIONS

Galectin-3 concentrations are elevated among adults with a Fontan circulation, and elevated galectin-3 is associated with an increased risk of nonelective cardiovascular hospitalization or death.

Imp3 expression in benign and malignant thyroid tumors and hyperplastic nodules

BACKGROUND

IMP3, a member of insulin-like growth factor II m RNA binding protein family, seems to be promising in the diagnosis of carcinomas of many organs as well as malignant melanomas and some sarcomas. It is postulated that it might be a marker of malignancy. The results of the few prior studies indicate that IMP3 has the potential to be useful in distinguishing benign and malignant tumors of thyroid.

AIMS

We aimed to evaluate the immunohistochemical expression of IMP3 in non-neoplastic nodules and benign and malignant tumors of the thyroid.

STUDY DESIGN

Diagnostic accuracy study.

METHODS

Overall, 92 thyroid lesions, including 22 nodular hyperplasia (NH), 14 follicular adenoma (FA), 9 follicular carcinoma (FC), 37 papillary carcinoma (PC) (15 follicular variant), 3 well differentiated carcinoma-not otherwise specified (WDC-NOS), 4 poorly differentiated carcinoma (PDC) and anaplastic carcinoma (AC) were included. Immunohistochemically, cytoplasmic expression of IMP3 was evaluated in terms of extent and intensity of the staining semi-quantitatively and an immunohistochemical score (IHS) was obtained for each case. A score higher than 2 was considered positive staining.

RESULTS

In contrast with previous studies, we observed positive staining in benign lesions, especially in benign tumors. For identifying malignant tumors, the sensitivity of IMP3 was 82.1%, specificity was 33.3%, positive predictive value (PPV) was 65.7% and negative predictive value (NPV) was 54.5%. In distinguishing neoplastic and hyperplastic lesions, the sensitivity was 50%, specificity was 15.7%, PPV was 15.7% and NPV was 50%. The IMP3 expression was similar for FA and well differentiated carcinomas (p=0.434), but there was a significant difference between hyperplastic nodules and FA (p=0.011).

CONCLUSION

Our data suggest that IMP3 is effective in discriminating hyperplastic and neoplastic lesions but not useful in differentiating benign tumors from malignant tumors.

Immunohistochemical expression of HBME-1 and galectin-3 in the differential diagnosis of follicular-derived thyroid nodules

BACKGROUND

Thyroid nodules are common among adults with only a small percentage being malignant and histologically mimic benign nodules. Accurate diagnosis of these thyroid nodules is critical for the proper clinical management. The determination of malignancy in follicular patterned thyroid lesions is based on postoperative histological findings. Therefore, affected patients are referred for surgery, although only 10% will have a final diagnosis of malignancy. The aim of this study was to investigate the ability of two immunohistochemical (IHC) markers; galectin-3 and Hector Battifora mesothelial-1 (HBME-1) individually or in combination, to distinguish between benign (non-neoplastic and neoplastic) and malignant (follicular and papillary carcinomas) thyroid lesions removed by surgical resection.

METHODS

We investigated the immunoexpression of galectin-3 and HBME-1 in 50 cases of benign and malignant thyroid nodules. The benign group included 13 cases of thyroid nodular goiter (NG) and 9 cases of follicular adenoma (FA). The malignant group included 5 cases of follicular thyroid carcinomas (FC), 18 cases of classic papillary thyroid carcinoma and 5 cases of follicular variant papillary carcinoma (FVPC).

RESULTS

The staining results showed that malignant tumors expressed galectin-3 and HBME-1 significantly more than benign nodules. The sensitivity of these markers for the distinction between benign and malignant lesions ranged from 89.3% to 92.9%. Co-expression of galectin-3 and HBME-1 was seen in 82.1% of carcinomas, but in none of the benign nodules. Immunoexpression was usually diffuse in malignant tumors, and focal in the benign lesions.

CONCLUSION

Our findings indicate that these immunohistochemical markers are significantly more expressed in malignant tumors compared to benign lesions and may be of additional diagnostic value when combined with routine histology. Galectin-3 has higher sensitivity and specificity of immunoexpression in thyroid malignancy than HBME-1, and the combined use of galectin-3 and HBME-1 can increase the specificity of immunoexpression in malignant tumors.

Risk stratification in follicular neoplasm: a cytological assessment using the modified Bethesda classification

BACKGROUND

The 2007 Bethesda classification for thyroid cytology defines follicular neoplasm as a category of cases with cellular specimens demonstrating abundant follicular cells arranged in a microfollicular pattern with little or no colloid. The current recommendation for the management of these cases is diagnostic lobectomy. There has been great difficulty and variability in triaging and reporting follicular neoplasm. To increase diagnostic accuracy, at the study institution, this category is subclassified further into 3 categories: 1) microfollicular-patterned neoplasm (MN); 2) Hürthle cell neoplasm (HN); and 3) follicular lesion with some features suggestive of but not diagnostic of the follicular variant of papillary thyroid carcinoma (FL). The authors reviewed the cases of follicular neoplasm observed over a period of 5 years to document the follow-up trend using this modified classification.

METHODS

A search of the cytology records was performed for the period between January 2008 and December 2012. All thyroid fine-needle aspiration cases were reviewed and those with a diagnosis of follicular neoplasm (including Hürthle cell neoplasm) were identified. Correlating follow-up surgical pathology reports were reviewed.

RESULTS

A total of 399 cases of follicular neoplasm with surgical follow-up were identified. Malignancy was identified in 32% of all cases of follicular neoplasm and was found to be disproportionately higher in the FL category (73%). A cytological diagnosis of FL is more likely to be called malignant (73%) than benign neoplastic (9%) or benign nonneoplastic (18%). A cytological diagnosis of MN or HN is more likely to be benign neoplastic (46% and 46%, respectively) than malignant (29% and 26%, respectively) or benign nonneoplastic (25% and 28%, respectively). Of the cytological features examined, 2 (nuclear enlargement and nuclear grooves) were significantly associated with the follicular variant of papillary thyroid carcinoma.

CONCLUSIONS

The results of the current study clearly indicate that follicular lesions with even subtle nuclear atypia have a high positive predictive value for malignancy and therefore should be distinguished from other follicular lesions because these cases require more aggressive surgical management. The current study also raises an important issue concerning the current thyroid classification based on the 2007 Bethesda classification for thyroid cytology. Future thyroid fine-needle aspiration classification schemes should consider subclassifying follicular neoplasms for the purpose of risk stratification.

Diagnostic biomarkers of differentiated thyroid cancer

The incidence of thyroid cancer has been increasing all around the world in the past decades. Early detection is one of the keys to reduce the mortality. Currently, fine-needle aspiration (FNA) guides the management of patients with a thyroid nodule. The use of FNA can reduce unnecessary thyroid surgery by twenty-five percent. However, the prevalence of non-diagnostic and indeterminate cytology from FNA is still high, approximately thirty percent. Many biomarkers were developed to differentiate between the benign and malignant thyroid nodule. This review summarizes each diagnostic biomarker of differentiated thyroid cancer. Sensitivity, specificity, and positive and negative predictive values of individual cytological laboratory need to be considered before implementation of each biomarker. Moreover, follow-up is still mandatory in negative biomarker tests because all genomic and proteomic alterations in thyroid cancer are still unknown.

CXC motif ligand 12 as a novel diagnostic marker for papillary thyroid carcinoma

BACKGROUND

We subjected chemokine (C-X-C motif) ligand 12 (CXCL12) to immunohistochemistry to determine its utility as a novel diagnostic marker for papillary thyroid carcinoma (PTC) in comparison to cytokeratin 19 (CK19), Hector Battifora mesothelial epitope-1 (HBME-1), and galectin-3.

METHODS

We analyzed the expressions of CXCL12, CK19, HBME-1, and galectin-3 using immunohistochemical staining in 258 cases of thyroid lesions (196 PTCs and 62 thyroid lesions excluding PTC).

RESULTS

Remarkably, CXCL12 expression was exclusively found in PTC compared to other thyroid lesions (90.8% vs 3.2%; p < .001). In total, 91.1% (62 of 68) of the variant PTCs and 90.6% of conventional type (116 of 128) were associated with CXCL12 immunohistochemical expression, irrespective of the histological subtype. In contrast, very few of the thyroid lesions, excluding PTC, were positive for CXCL12 (2 of 62; 3.2%). Diagnostic performances for PTCs were as follows: sensitivity, 90.8%; specificity, 96.8%; positive predictive value, 98.9%; negative predictive value, 76.9%; and diagnostic accuracy, 92.2%.

CONCLUSION

Our findings indicate that CXCL12 might serve as an effective novel supplementary diagnostic marker for PTC.

Methodology and technical requirements of the galectin-3 test for the preoperative characterization of thyroid nodules

In the last decade, the β-galactosyl binding protein galectin-3 has been the object of extensive molecular, structural, and functional studies aimed to clarify its biological role in cancer. Multicenter studies also contributed to discover the potential clinical value of galectin-3 expression analysis in distinguishing, preoperatively, benign from malignant thyroid nodules. As a consequence galectin-3 is receiving significant attention as tumor marker for thyroid cancer diagnosis, but some conflicting results mostly owing to methodological problems have been published. The possibility to apply preoperatively a reliable galectin-3 test method on fine needle aspiration biopsy (FNA)-derived thyroid cells represents an important achievement. When correctly applied, the method reduces consistently the gray area of thyroid FNA cytology, contributing to avoid unnecessary thyroid surgery. Although the efficacy and reliability of the galectin-3 test method have been extensively proved in several studies, its translation in the clinical setting requires well-standardized reagents and procedures. After a decade of experimental work on galectin-3-related basic and translational research projects, the major methodological problems that may potentially impair the diagnostic performance of galectin-3 immunotargeting are highlighted and discussed in detail. A standardized protocol for a reliable galectin-3 expression analysis is finally provided. The aim of this contribution is to improve the clinical management of patients with thyroid nodules, promoting the preoperative use of a reliable galectin-3 test method as ancillary technique to conventional thyroid FNA cytology. The final goal is to decrease unnecessary thyroid surgery and its related social costs.

Risk stratification of indeterminate thyroid fine-needle aspiration biopsy specimens based on mutation analysis

BACKGROUND

Mutation analysis is potentially a powerful tool to enhance the diagnostic accuracy of thyroid fine-needle aspiration (FNA) biopsy specimens. However, some clinicians may rely on a negative mutation panel to exclude malignancy. We aimed to determine the malignancy rate in indeterminate lesions with negative mutation analysis.

METHODS

A literature review established a mutation analysis model using the prevalence of BRAF, RET, RAS, and PAX8/peroxisome proliferator-activated receptor-γ mutations in indeterminate lesions. This model was applied retrospectively to a study cohort of 466 consecutive indeterminate lesions that underwent hemi- or total thyroidectomy for definitive diagnosis, to evaluate its accuracy for identifying malignancy.

RESULTS

Of 466 indeterminate lesions in the study, 30% (139) were malignant. These included 66 cases of papillary thyroid cancer, 45 cases of follicular variant of papillary thyroid cancer, 18 cases of follicular thyroid cancer, and 10 others. The risk of malignancy was 42% when cytologic atypia was present vs 17% without. The mutation analysis model would correctly identify only 48 of 139 (34%) of malignant indeterminate lesions. Therefore, when mutation analysis is negative, the overall risk of malignancy would be 23%. When atypia is present, the risk of malignancy would be 31% vs 13% in lesions without.

CONCLUSION

Indeterminate lesions with a negative mutation analysis still carry a significant risk of malignancy, especially in the presence of atypia, requiring surgery for definitive diagnosis.

Update on the molecular signature of differentiated thyroid cancer: clinical implications and potential opportunities

With the development and maturation of new technologies, there has been a steady incorporation of powerful new tools into the evaluation and management of thyroid nodules and thyroid cancer. An increasing number of reports on oncogene testing and molecular screening in fine-needle aspiration biopsy samples have been published. However, there remains a paucity of data and consensus on combining both conventional and molecular technologies to determine the diagnosis and/or prognosis of disease. All patients with differentiated thyroid cancer stand to benefit from the identification and incorporation of reliable molecular markers into clinical practice. Identification of reliable markers would allow for stratification of treatment, affording the medical and surgical teams an ability to individually tailor evaluation and treatment, applying aggressive therapy and monitoring only when clinically warranted. For the majority of patients with thyroid cancer, the incorporation of a validated, multifaceted molecular profiling system may not improve survival; however, there is great opportunity for these efforts to decrease the morbidity associated with our current approach.

Well differentiated follicular thyroid neoplasia: impact of molecular and technological advances on detection, monitoring and treatment

Our understanding of the molecular mechanisms responsible for follicular thyroid cell oncogenesis has been advanced significantly in recent years. Specific genetic alterations and the molecular pathways they affect have been associated with particular histologic subtypes of well-differentiated thyroid cancer and are now being evaluated for their utility as clinical tools with diagnostic, prognostic and even therapeutic relevance. This paper focuses on the most common and clinically relevant genetic alterations shown to be consistently associated with well-differentiated thyroid carcinoma. We review the impact of recent molecular and technological advances on thyroid cancer standard of care and the practice of clinical medicine.

Galectins as cancer biomarkers

Galectins are a group of proteins that bind β-galactosides through evolutionarily conserved sequence elements of the carbohydrate recognition domain (CRD). Proteins similar to galectins can be found in very primitive animals such as sponges. Each galectin has an individual carbohydrate binding preference and can be found in cytoplasm as well as in the nucleus. They also can be secreted through non-classical pathways and function extracellularly. Experimental and clinical data demonstrate a correlation between galectin expression and tumor progression and metastasis, and therefore, galectins have the potential to serve as reliable tumor markers. In this review, we describe the expression and role of galectins in different cancers and their clinical applications for diagnostic use.

Diagnostic utility of galectin-3 in thyroid cancer

Galectin-3 (Gal-3), which has received significant recent attention for its utility as a diagnostic marker for thyroid cancer, represents the most well-studied molecular candidate for thyroid cancer diagnosis. Gal-3 is a protein that binds to beta-galactosidase residues on cell surface glycoproteins and has also been identified in the cytoplasmic and nuclear compartment. This marker has been implicated in regulation of normal cellular proliferation and apoptosis, as well as malignant transformation and the metastasis of cancer cells. We here present a mechanistic review of Gal-3 and its role in cancer development and progression. Gal-3 expression studies in thyroid tissue and cytologic tumor specimens and their methodological considerations are also discussed in this article. Despite great variance in their methodology, the majority of immunohistochemical studies found that Gal-3 was differentially expressed in thyroid carcinoma compared with benign and normal thyroid specimens, suggesting that Gal-3 is a good diagnostic marker for thyroid cancer. Recent studies have also demonstrated improved methodological reliability. On the other hand, Gal-3 genomic expression studies have shown inconsistent results for diagnostic utility and are not recommended. Overall, the development of Gal-3 as a diagnostic marker for thyroid cancer represents a promising avenue for future study, and its clinical application could significantly reduce the number of diagnostic thyroid operations performed for cases of indeterminant fine needle aspiration biopsy cytology, and thus positively impact the current management of thyroid nodular disease.

Molecular markers in thyroid cancer diagnostics

Although fine-needle aspiration biopsy (FNA) remains the mainstay of the preoperative workup of thyroid nodules, it does not provide a diagnosis in up to 20% of nodules. This group of indeterminate lesions, including lesions with cellular atypia, suspicious cytology, and demonstrating a follicular pattern, provides one of the greatest challenges to researchers in thyroid cancer today. Over the last 2 decades, considerable work has been done to find molecular markers to resolve this diagnostic dilemma. This article explores some of the markers including galectin-3, HBME-1, BRAF, RET/PTC, PAX8-PPARgamma, hTERT, telomerase, miRNA, and microarray and multigene assays. Although no one marker has proven to be a panacea, several combinations of markers have shown great promise as an adjunct to FNA.

Insulin-like growth factor mRNA binding protein 3 (IMP3) is differentially expressed in benign and malignant follicular patterned thyroid tumors

Insulin-like growth factor mRNA binding protein 3 (IMP3) is an mRNA-binding protein that regulates transcription of insulin-like growth factor II affecting cell proliferation during embryogenesis. It is highly expressed in carcinomas of the pancreas, stomach, colon, rectum, kidneys, uterine cervix, lung, and ovary. The purpose of our study was to evaluate IMP3 expression in thyroid follicular lesions, to determine whether it has a role in differentiating among these lesions, and to understand their biological relationships. We immunostained 219 thyroid lesions selected from our surgical pathology archives including 14 hyperplastic colloid nodules (CN), 19 Hashimoto's thyroiditis (HT), two Graves disease (GD), ten Hürthle cell adenoma (HCA), 20 follicular adenoma (FA), 37 conventional papillary thyroid carcinoma (PTC), 60 follicular variant of papillary carcinoma (FVPC), 19 Hürthle cell carcinoma (HCC), 32 follicular carcinoma (FC), and six poorly differentiated/anaplastic carcinoma. Immunohistochemistry was performed on formalin-fixed sections using monoclonal antibody to IMP3. Clinicopathological data were also reviewed. In all cases, residual thyroid tissue, CN, HT, GD, HCA, and FA were completely negative for IMP3 staining. Of the 60 FVPC, 23 tumors (38%) were positive for IMP3, with 13 of these (22%) showing very strong staining (3+). Of the 32 FC, 22 tumors (69%) were positive, with seven (22%) showing very strong staining (3+). Furthermore, 33 out of 37 cases (89%) of PTC were negative for IMP3. In all four PTC cases that did stain positive, staining was weak-moderate (1-2+). Similarly, 15 out of 19 cases (79%) of HCC were negative. No significant correlation was found between pathologic tumor characteristics and IMP3 expression in differentiated follicular pattern thyroid carcinoma. With 100% specificity and 69% sensitivity for FC as compared to FA and 100% specificity for FVPC, again compared to FA, IMP3 has the potential to be diagnostically useful in differentiating malignant and benign follicular pattern thyroid lesions. This study also points to a possible common biological relationship between FC and FVPC that requires further investigation.

Trefoil factor 3 (TFF3): a promising indicator for diagnosing thyroid follicular carcinoma

Since the introduction of fine needle aspiration biopsy (FNAB) in the 1970's, a preoperative diagnostic technique for thyroid follicular carcinoma has long been awaited. Many markers that distinguish follicular carcinomas from adenomas have been reported; however, most of them have not been confirmed to be beneficial for clinical use. Trefoil factor 3 (TFF3) is a relatively new family of peptides that bears the three-loop trefoil domain. Several groups have reported that the suppression of TFF3 mRNA expression is related to malignant characteristics of thyroid follicular cell-derived tumors and the expression level of TFF3 mRNA is the most promising indicator for diagnosing follicular carcinoma. Development of TFF3-based diagnostic methods is now ongoing and it may not be long before thyroid follicular carcinoma can be diagnosed preoperatively using an aspirated sample from the tumor.

Potential diagnostic markers in nodular lesions of the thyroid gland: an immunohistochemical study

AIMS

The differential diagnosis of thyroid nodules in routine practice can be problemmatic for both pathologists and clinicians. Effective treatment requires a determination of the biological nature of the lesions. For this reason, ancilliary diagnostic markers along with histological examination of the nodules may be useful. The objective of this study was to evaluate the diagnostic usefulness of novel markers in the diagnosis of hyperplastic and neoplastic nodules.

METHODS

Forty eight thyroid lesions forming four diagnostic groups including adenomatous goiters (AS), follicular adenomas (FA), follicular (FC) and papillary carcinomas (PC) were examined using standard immunohistochemical methods. Monoclonal antibodies against galectin-3, matrix metalloproteinases (MMPs) -2 and -7 and endothelial markers CD31 and CD105 were used.

RESULTS

The cytoplasmatic expression of galectin-3 was positive in all cases of papillary carcinoma. Moreover, statistically significant differences between fused groups of benign (AS and FA) and malignant lesions (FC and PC) were found Fischer's exact test (p = 0.0001). No significant differences in cytoplasmic expression of MMPs -2 and -7 and in vascular density assessed by using of both endothelial markers between benign lesions and malignant tumors were revealed.

CONCLUSIONS

Galectin-3 appears to be a useful marker in the diagnosis of papillary carcinoma only. The matrix metalloproteinases-2 and -7 are not helpful in distinguishing hyperplastic and neoplastic thyroid nodules. Endothelial markers do not appear to be suitable for thyroid differential diagnosis. A panel of antibodies in the differential diagnosis of thyroid nodular lesions would seem most suitable and further studies with larger sets of patients are awaited.

Do benign thyroid nodules have malignant potential? An evidence-based review

BACKGROUND

Benign thyroid tumors account for most nodular thyroid disease. Determination of whether a thyroid nodule is benign or malignant is a major clinical dilemma and underlies the decision to proceed to surgery in many patients. Although the accuracy of thyroid nodule fine-needle aspiration (FNA) has reduced the need for surgery over the years, questions regarding how to follow FNA-designated benign nodules remain unresolved. This is true at least in part because of uncertainty over whether some benign nodules harbor malignant potential.

METHODS

An evidence-based review of recent clinical, pathologic, and molecular data is presented. A summary of data and observations from our own experience is also provided.

RESULTS

Review of our recent 10-year experience indicates that 2% of thyroid malignancies arise within a preexisting benign thyroid nodule. In addition, both cytologic and molecular tumor markers, including Gal-3, CITED1, HBME-1, Ras, RET/PTC, and PAX8/PPAR gamma, have been identified in some histopathologically classified benign nodules. Gene expression profiling suggests that follicular adenomas and Hürthle cell adenomas have similarities to both benign and malignant tumors, suggesting that some of these tumors are premalignant. In addition, 10% of surgically excised follicular tumors are encapsulated follicular lesions with nuclear atypia, which have been termed "well-differentiated tumors of uncertain malignant potential." The data available suggest that these tumors could be precursors to carcinoma.

CONCLUSION

Some benign thyroid nodules have malignant potential. Further molecular testing of these tumors can shed light on the pathogenesis of early malignant transformation.

Evaluation of galectin-8 expression in thyroid tumors

The expression of galectin-8 (gal-8) has been shown to be altered during neoplastic transformation of certain cell types. This is the first study aimed to analyze the expression of this protein in normal and pathological human thyroid tissue. A total of 41 archival thyroid tissue samples (5 follicular adenomas, 31 papillary carcinomas, 5 follicular carcinomas) together with 36 adjacent hyperplastic or normal thyroid tissues were analyzed by immunohistochemistry. Galectin-8 was expressed in the majority of papillary carcinomas (27/31; 87%). Positive but weaker staining was also found in some of the follicular thyroid carcinomas (2/5; 40%) and adenomas (2/5; 40%). This protein was not detectable in five normal thyroid tissue samples, whereas hyperplastic areas adjacent to tumor were weakly positive in 9 out of 31 cases (29%). High gal-8 immunostaining in papillary thyroid carcinoma indicates that gal-8 may potentially serve as a marker of papillary thyroid carcinoma. However, it does not seem to be helpful in the differential diagnostics of follicular carcinoma and adenoma. Further studies are required to determine biological functions and molecular mechanisms underlying the increased expression of gal-8 protein in thyroid lesions, particularly, in papillary thyroid carcinoma.

Molecular phenotyping of thyroid tumors identifies a marker panel for differentiated thyroid cancer diagnosis

BACKGROUND

Currently, a large proportion of individuals undergo thyroidectomy as a diagnostic procedure for cancer. The objective of this work was to evaluate the molecular phenotype of differentiated thyroid cancer (DTC) and benign thyroid lesions to identify molecular markers that allow for accurate thyroid cancer diagnosis.

METHODS

Tissue microarrays consisting of 100 benign and 105 malignant thyroid lesions, plus 24 lymph node samples, were stained for a panel of 57 molecular markers. Significant associations between marker staining and tumor pathology (DTC versus benign) were determined using contingency table and Mann-Whitney U (MU) tests. A Random Forests classifier algorithm was also used to identify useful/important molecular classifiers.

RESULTS

Of the 57 diagnostic markers evaluated 35 (61%) were significantly associated with a DTC diagnosis after multiple testing correction. Of these, in DTC compared with benign thyroid tumors, 8 markers were downregulated and 27 upregulated. The most significant markers for DTC diagnosis were: Galectin-3, Cytokeratin 19, Vascular Endothelial Growth Factor, Androgen Receptor, p16, Aurora-A, and HBME-1. Using the entire molecular marker panel, a Random Forests algorithm was able to classify tumors as DTC or benign with an estimated sensitivity of 87.9%, specificity of 94.0%, and an accuracy of 91.0%.

CONCLUSION

Evaluation of the DTC and benign thyroid tumor molecular phenotype has allowed for identification of a marker panel, composed of both established and novel markers, useful for thyroid cancer diagnosis. These results suggest that further study of the molecular profile of thyroid tumors is warranted, and a diagnostic molecular marker panel may potentially improve patient selection for thyroid surgery.

Serum galectin-1 and galectin-3 levels in benign and malignant nodular thyroid disease

BACKGROUND

Since the histological expression of galectins is increased in thyroid carcinoma, determination of their serum levels may provide useful preoperative information. The goal of this study was to determine if a difference in galectin serum levels could be detected between benign and malignant nodular thyroid diseases.

DESIGN

Using validated ELISAs, the concentrations of several galectins were prospectively measured in serum samples from 30 healthy individuals and preoperatively in 90 patients with thyroid disease. Seventy-one patients had multiple thyroid nodules (MTN), 13 patients had a single thyroid nodule (STN), and 6 patients had Graves' disease. Nine of 71 patients with MTN had fine-needle aspiration biopsy (FNAB) of their nodules and in 7 patients a "benign" diagnosis was made, in 0 patient a "malignant" diagnosis was made, and in 2 patients a "suspicious" diagnosis was made. Six of 13 patients with STN had FNAB of their nodules and in 2 patients a "benign" diagnosis was made, in 3 patients a "malignant" diagnosis was made, and in 1 patient a "suspicious" diagnosis was made.

RESULTS

Thyroid disease was associated with higher levels of galectins-1 and -3 compared to normal subjects. Using a threshold value of 3.2 ng/mL as a cut-off point, the measurement of serum galectin-3 separated micro- and macropapillary thyroid carcinoma (PAP_CA) from patients with nonmalignant thyroid disease with 74% specificity, 73% sensitivity, 57% positive predictive value, and 85% negative predictive value. Elevated serum galectin-3 concentrations (>3.2 ng/mL) detected 87% of macropapillary thyroid carcinomas and 67% of micropapillary thyroid carcinomas.

CONCLUSIONS

Serum levels of galectins-1 and -3 are relatively high in patients with thyroid malignancy but there is considerable overlap in serum galectin-3 concentrations between those with benign and malignant nodular thyroid disease and, to a lesser extent, between those with and without nodular thyroid disease.

What is New on Thyroid Cancer Biomarkers

Thyroid cancer harbours in about 5% of thyroid nodules. The majority of them are well-differentiated cancers originating from the follicular epithelium, and are subdivided into papillary and follicular carcinomas. Undifferentiated carcinomas and medullary thyroid carcinomas arising from C cells are less common.

Although most thyroid nodules are benign, distinguishing thyroid cancer from benign lesions is crucial for an appropriate treatment and follow-up. The fine needle aspiration cytology (FNAC) allows the diagnosis of nature of thyroid nodules in the majority of cases. However, FNAC has some limitations, particularly in the presence of follicular lesions which can appear dubious in rare instances even at histology.

In an effort to improve diagnostic accuracy and offer new prognostic criteria, several immunohistochemical and molecular markers have been proposed. However, most of them have to be validated on large series before being used in routine practice.

The significance of Galectin-3 expression in the immunocytochemical evaluation of thyroid fine needle aspiration cytology

The aim of this study is to evaluate the significance of immunohistochemical expression of Galectin-3 in the differential diagnosis of benign and malignant thyroid nodules. We studied the fine needle aspiration specimens of 38 patients who had evaluated for nodular goiter and undergone a thyroid surgery between 2004-2005. Slides had been stained immunocytochemically with Galectin-3. The cytoplasmic staining of Galectin-3 was analyzed. Three cases of five follicular carcinomas had positive staining for Galectin-3, while two had not. Two cases with follicular adenomas were negative for Galectin-3. Five cases of six papillary carcinomas had positive staining for Galectin-3, while one case (the case with a papillary microcarcinoma) had not. The single cases with medullary and anaplastic carcinomas were negative for Galectin-3. None of the cases with a benign thyroid pathology had positive staining for Galectin-3. Galectin-3 immunocytochemical staining, had a sensitivity of 61.5%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 83.3% for thyroid malignancies. For the evaluation of follicular neoplasm, Galectin-3 immunocytochemical staining had a sensitivity of 60%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. Galectin-3 expression in thyrocytes is a strong indicator of a malignant proliferative lesion especially for papillary and to an extent in follicular thyroid neoplasms. Galectin-3 could be used as a supplementary marker for cytological diagnosis.

Controversies in thyroid pathology: the diagnosis of follicular neoplasms

Thyroid nodules are common; almost 20% of the population has a palpable thyroid nodule and approximately 70% has a nodule detected by ultrasound. Thyroid cancer is the most frequent endocrine malignancy, and incidence rates have steadily increased over the last decades. Papillary carcinoma (PTC) is the most common malignant neoplasm of the thyroid; the diagnosis of this most frequent type (85-90%) has been increasing, possibly due to changing recognition of morphologic criteria. PTC is defined histologically as a malignant tumor showing evidence of follicular epithelial differentiation and characterized by distinctive nuclear features. However, there are borderline lesions that do not completely fulfill these criteria, making the diagnosis difficult. The use of immunohistochemical and molecular markers adds objective criteria to this confusing and controversial area of pathology. We review the differential diagnosis of well-differentiated follicular thyroid neoplasms and the ancillary techniques and molecular characteristics that have been proposed for application in the diagnosis of PTC.

Is galectin-3 a good method for the detection of malignancy in patients with thyroid nodules and a cytologic diagnosis of “follicular neoplasm”? A critical appraisal of the evidence

BACKGROUND

Thyroid nodules are the most common surgical disease of the thyroid. Fine-needle aspiration biopsy (FNAB) is the most commonly employed tool for establishing a diagnosis. However, 15% to 25% of FNAB reports yield inconclusive results. Immunostaining of cytological smears from FNAB with galectin-3 has been proposed as a tool for differentiating between benign and malignant nodules. We performed a systematic review to evaluate the utility of galectin-3.

METHODS

Prospective studies of nodules with FNAB reports of "follicular neoplasm" and with a definitive diagnosis confirmed by histopathology were selected. Calculations of individual sensitivity, specificity, and positive and negative likelihood ratios were made.

RESULTS

The articles selected were those with the best methodological quality.

CONCLUSION

Galectin-3 could be a good tool to guide therapeutic decision in patients with thyroid nodules and FNAB results of follicular neoplasm, but available information has methodological flaws that precludes a definitive answer about galectin-3 utility in the clinical setting.

Follicular neoplasm of the thyroid--vanishing cytologic diagnosis?

The significance of making a diagnosis of follicular neoplasm on fine needle aspiration (FNA) biopsy remains a controversial issue, considering that the diagnosis of follicular carcinoma is based on histological criteria and the significantly decreasing incidence of follicular carcinoma in the general population. On FNA the main differential diagnoses of follicular neoplasm includes follicular variant of papillary carcinoma (FVPC), follicular adenoma, follicular carcinoma and benign solitary nodule occurring in a goiter. Several studies have looked at immunohistochemical and molecular markers to distinguish benign from malignant lesions but none of them have proved to be infallible. Although, FVPC is a distinct entity from the follicular neoplasm group, it is not always possible to separate it from the other follicular lesions because of overlapping cytologic features and often-sporadic presence of nuclear features, follicular variant of papillary carcinoma remains the main pitfall in a diagnosis of follicular neoplasm. Since a significant number of cases that are malignant on follow-up are usually FVPC, consequently, follicular neoplasm is an essential diagnostic consideration on FNA. In addition, follicular carcinoma, despite a decreasing incidence continues to be a real entity. Therefore, it is essential that follicular neoplasm continue to be part of our diagnostic repertoire.

Papillary microcarcinoma of the thyroid gland: is the immunohistochemical expression of cyclin D1 or galectin-3 in primary tumour an indicator of metastatic disease?

INTRODUCTION

Papillary microcarcinomas (PMC) of the thyroid gland are defined according to The WHO Committee as papillary carcinomas measuring 10 mm or less in diameter. A large proportion of these tumours are found coincidentally in the treatment of symptomatic goitre and most cases follow an indolent course with an excellent prognosis. However, a more aggressive behaviour with regional and distant metastases does occur. The aim of this study was to evaluate if the immunohistochemical markers cyclin D1 or galectin-3 might indicate the presence of metastatic disease in patients with PMC at the time of diagnosis.

MATERIAL AND METHODS

From the 1(st) of January 1996 to 31(st) of December 2002 a total of 169 PMC patients were diagnosed and registered in the national Danish thyroid cancer database DATHYRCA and 131 of these were eligible for the study. Forty-three (33%) had histologically verified regional or distant metastases. Slides were cut from the primary tumour and immunostaining and quantification was subsequently performed.

RESULTS

The percentage of positive cells was examined for patients with and without metastases. For cyclin D1 the median values were 31% (range: 0-59) and 21% (range: 0-75), respectively, showing a statistically significant difference (p=0.02). For galectin-3 the medians were 87% (range: 6-96) and 85% (range: 0-99) and no significant difference was found.

CONCLUSION

Cyclin D1 showed significantly higher median expression in patients with metastases compared to those without, indicating a correlation to tumour aggressiveness. However, both groups showed large variation in expression, which disqualify the marker as a discriminator for the detection of metastases. Galectin-3 was without any significant correlation to the presence of metastases from PMC.

Percutaneous large-needle aspiration biopsy histology of palpable thyroid nodules: technical and diagnostic performance

AIM

To report original and review existing data on safety and performance of large-needle aspiration biopsy (LNAB) histology in the preoperative selection of palpable thyroid nodule.

METHODS AND RESULTS

The English literature and original data were reviewed or analysed. The literature on LNAB of thyroid nodules did not report any complications. A study on needle dimensions has explained why LNAB obtains more tissue than fine-needle aspiration (FNA) and is safe. LNAB histology has higher specificity than FNA cytology and markedly reduces the number of inadequate and indeterminate FNA findings. A comparison of 150 FNA-derived cell blocks with 200 LNAB-derived histological blocks after galectin-3 determination in a large nationwide (Italian) study has shown that one to two sections in 10% of the FNA cell blocks and at least five sections in 90% of the LNAB blocks were available for further determinations of thyroid tumour markers.

CONCLUSION

LNAB merits further consideration for the preoperative selection of thyroid nodules.

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.

Galectin-3 immunoprofile in adenoid cystic carcinoma and polymorphous low-grade adenocarcinoma of salivary glands

Adenoid cystic carcinoma (ACC) and polymorphous low-grade adenocarcinoma (PLGA) are malignant neoplasms of salivary glands, which are similar in histologic patterns but very different in clinical behavior, treatment and prognosis. Galectin-3 is a multifunctional protein of a growing family of beta-galactoside-binding animal lectins, which is implicated in a variety of biological events such as tumor cell adhesion, proliferation, differentiation and angiogenesis. This protein was found to be implicated in cellular transformation and a correlation between its expression and cancer progression and metastasis has been described. The aim of this study was to determine the galectin-3 immunoprofile in 14 cases of ACC (2 cases of tubular subtype, 4 cases of solid subtype and 8 cases of cribriform subtype) and in 12 cases of PLGA with different histologic patterns, including lobular, tubular and cribriform aspects. Moreover, slides of normal salivary glands were included. In normal salivary glands there was strong nuclear and cytoplasmic staining for galectin-3 in ductal luminal cells. ACC showed specific staining in luminal cells mainly in the nuclei. In the tubular subtype of ACC, galectin-3 strongly stained luminal cells of the ductiform structures. The cribriform and solid subtypes showed a few positive luminal cells of small ducts present in the cribriform structures and in solid nests respectively. In the cases of PLGA, independent of the histologic architecture, all tumor cells revealed a positive cytoplasmic reaction. Galectin-3 expression seems to be related to cell differentiation more than to tumor progression and prognosis in the neoplasms studied.

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.