Diagnosis Of Follicular Thyroid Carcinoma Research Articles

Preoperative clinical and paraclinical features and neck lymph metastasis in patients with follicular thyroid cancer undergoing surgery in National Hospital of Endocrinology

Background: Follicular thyroid cancer has a low rate of lymph node metastasis compared to other types. However, cervical lymph node metastasis is a risk factor for recurrence and distant metastasis, affecting the patient's prognosis. The study aims to evaluate the clinicopathologic features and metastasis states of follicular thyroid carcinoma at National hospital of Endocrinology. Methods: We conducted a retrospective cohort study of 64 follicular thyroid carcinoma patients treated by surgery at National hospital of Endocrinology from June 2017 to March 2019. Results: The mean age was 45,5 ± 13,1 and the female/male ratio was 15/1. Most patients presented with an asymptomatic and had a unilateral tumor with mean diameter was 15, 09 ± 8,42 mm. 73,4% of tumors were classifled as TIRADS 4 on ultrasound. FNA was not of great significance for diagnosis of follicular thyroid carcinoma with undetermined significance result in 40,6%. The overall rate of nodal metastasis was 29,7%, higher with cancer surgery in both lobes of the thyroid gland. Conclusions: Follicular thyroid cancer has a higher rate of cervical lymph node metastasis in patients aged 55 years and older, with tumors in both lobes and larger than 2 cm. However, cervical lymph node metastasis in follicular thyroid cancer is lower than in other thyroid cancers and cytology is not of high value in preoperative diagnosis.

Abstract 6273: GGCT expression is a useful marker for the diagnosis of follicular thyroid carcinoma

Abstract Background: Follicular thyroid carcinoma (FTC) and follicular adenoma (FA) have similar histological findings. FTC is distinct from FA based on the presence of capsular or vascular invasion in the tissues, but it is difficult to confirm the diagnosis in some cases. In this study, we aimed to establish useful molecular maker for differential diagnosis between FTC and FA. Methods: This study included FTC (n = 32), FA (n = 64), and follicular tumors of uncertain malignant potential (FT-UMP, n = 5). Invasive front tissue and tumor center tissue from 3 cases of FTC were collected using a laser microdissection system; RNA was extracted, followed by microarray analysis to examine molecules that were commonly highly expressed in the invasive front. Subsequently, immunohistochemical staining of gamma-glutamyl cyclotransferase (GGCT) was performed. For assessment of GGCT expression, the intensity of the nuclear staining was stratified using a four-tiered scale (0 to 3) and percentage of positive cells (0-100%) in the hotspot. Multiplying intensity score and percent of positive cells, an expression score ranging from 0 to 300 was calculated. The Ki-67 labeling index was examined in 20 cases of FTC, 25 cases of FA, and 4 cases of FT-UMP from the same cohort. We counted at least 2,000 tumor cells in the hot spot for the assessment of Ki-67 labeling index. Results: Microarray analysis revealed GGCT exhibited high expression levels at the invasive front of FTC. In immunohistochemical assessment, GGCT expression scores were significantly higher in FTC than in FA (118.5 ± 51.4 vs. 57.3 ± 34.7, p < 0.0001). The median Ki-67 labeling index were 3.9% (range 0.2 - 16.1) for FTC and 2.4% (range 0.3 - 7.0) for FA. FTC showed a higher Ki-67 index than FA (Wilcoxon rank sum test, p = 0.0444). With GGCT expression score, applying a cutoff value of 101.1, the distinction between FTC and FA resulted in a sensitivity of 68.8% and a specificity of 87.5% (AUC: 0.832). With Ki-67 labeling index, applying a cutoff value of 4.0%, the distinction between FTC and FA resulted in a sensitivity of 50.0% and a specificity of 80.0% (AUC: 0.677). The GGCT expression score was positively related with the Ki-67 labeling index in the FTC cases. (Spearman's ρ = 0.5293, p = 0.0164). There were no significant associations between GGCT expression scores and clinicopathological parameters, including age, gender, tumor diameter, pT stage, pN stage, pattern of capsular invasion, number of foci of vascular invasion, and the presence of distant metastasis. Conclusions: GGCT is a potential marker for differentiating FTC from FA. The GGCT expression of FTC may contribute to estimating the invasive activity and proliferative activity. Citation Format: Toshiyuki Mitsuhashi, Sachiko Ogasawara, Masamichi Nakayama, Reiichiro Kondo, Jun Akiba, Kenta Murotani, Takeharu Ono, Fumihiko Sato, Hirohito Umeno, Hirohisa Yano. GGCT expression is a useful marker for the diagnosis of follicular thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6273.

Development and validation of a predictive model for assessing the risk of follicular carcinoma in thyroid nodules identified as suspicious by intraoperative frozen section.

Follicular thyroid carcinoma (FTC) is the second most common thyroid malignancy and is characterized by a higher risk of distant metastasis compared to papillary thyroid cancer. Intraoperative frozen section (IOFS) diagnosis of FTC is challenging due to its limited sensitivity and accuracy, leading to uncertainty in intraoperative surgical decision-making. In response, we developed a predictive model to assess the risk of follicular carcinoma in thyroid nodules identified as suspicious for follicular neoplasm by IOFS. This model was derived from preoperative clinical and ultrasound data of 493 patients who underwent thyroid surgery at Ningbo Medical Center Lihuili Hospital. It identified five significant predictors of follicular carcinoma: nodule size, thyroglobulin (Tg) level, hypoechogenicity, lobulated or irregular margins, and thick halo. The model demonstrated robust discrimination and calibration, with an area under the curve (AUC) of 0.83 (95% CI: 0.77-0.90) in the training set and 0.78 (95% CI: 0.68-0.88) in the validation set. In addition, it achieved a sensitivity of 81.63% (95% CI: 69.39-91.84) and 68.00% (95% CI: 48.00--4.00), a specificity of 77.42% (95% CI: 72.18-82.66) and 72.51% (95% CI: 65.50-78.96), an accuracy of 78.1% (95% CI: 73.4-82.4) and 71.9% (95% CI: 65.3-78.6), a positive predictive value (PPV) of 41. 67% (95% CI: 35.65-48.84) and 26.79% (95% CI: 19.40-34.33), respectively, and a negative predictive value (NPV) of 95.61% (95% CI: 92.86-97.99) and 94.07% (95% CI: 90.44-97.08) in the training and validation sets, respectively. The model can accurately rule out FTC in low-risk nodules, thereby providing surgeons with a practical tool to determine the necessary extent of surgical intervention for nodules flagged as suspicious by IOFS.

The potential value of LC-MS non-targeted metabonomics in the diagnosis of follicular thyroid carcinoma.

To explore the metabolic differences of follicular thyroid carcinoma (FTC) by metabonomics, to find potential biomarkers for the diagnosis of FTC, and to explore the pathogenesis and diagnosis and treatment strategies of FTC. The metabonomics of 15 patients with FTC and 15 patients with follicular thyroid nodules(FTN) treated in Henan Cancer Hospital were analyzed by liquid chromatography-mass spectrometry (LC-MS). The analysis showed that the metabolite profiles of FTC tissues could be well distinguished from those of control tissues, and 6 kinds of lipids were identified respectively, including lysophosphatidic acid(LysoPA) [LysoPA(0:0/18:0),LysoPA(0:0/18:2(9Z,12Z)],LysoPA[20:4(8Z,11Z,14Z,17Z)/0:0)]; phosphatidic acid(PA) [PA(20:3(8Z,11Z,14Z)/0:0),PA(20:4(5Z,8Z,11Z,14Z)/0:0),PA(20:5(5Z,8Z,11Z,14Z,17Z)/0:0)]; lysophosphatidylcholine(LPC) [LPC(18:1),LPC(16:0),LPC[16:1(9Z)/0:0],LPC(17:0),LPC[22:4(7Z,10Z,13Z,16Z),LPC(20:2(11Z,14Z); phosphatidylcholine(PC)(PC(14:0/0:0),PC(16:0/0:0); sphingomyelin(SM) (d18:0/12:0); fatty acid(FA)(18:1(OH3)]. There are 2 kinds of amino acids, including L-glutamate,L-glutamine.There are 3 other metabolites, including retinol,flavin adenine dinucleotide,androsterone glucuronide.Lipid metabolites are the main metabolites in these metabolites.The metabolic pathways related to FTC were analyzed by KEGG and HMDB, and 9 metabolic pathways were found, including 4 amino acid related metabolic pathways, 1 lipid metabolic pathways and 4 other related pathways. There are significant differences in many metabonomic characteristics between FTC and FTN, suggesting that these metabolites can be used as potential biomarkers. Further study found that LysoPA and its analogues can be used as biomarkers in the early diagnosis of FTC.It may be related to the abnormal metabolism of phospholipase D (PLD), the key enzyme of LysoPA synthesis caused by RAS pathway. At the same time, it was found that the metabolic pathway of amino acids and lipids was the main metabolic pathway of FTC. The abnormality of LysoPA may be the cause of follicular tumor carcinogenesis caused by lipid metabolic pathway.

Improve follicular thyroid carcinoma diagnosis using computer aided diagnosis system on ultrasound images.

We aim to leverage deep learning to develop a computer aided diagnosis (CAD) system toward helping radiologists in the diagnosis of follicular thyroid carcinoma (FTC) on thyroid ultrasonography. A dataset of 1159 images, consisting of 351 images from 138 FTC patients and 808 images from 274 benign follicular-pattern nodule patients, was divided into a balanced and unbalanced dataset, and used to train and test the CAD system based on a transfer learning of a residual network. Six radiologists participated in the experiments to verify whether and how much the proposed CAD system helps to improve their performance. On the balanced dataset, the CAD system achieved 0.892 of area under the ROC (AUC). The accuracy, recall, precision, and F1-score of the CAD method were 84.66%, 84.66%, 84.77%, 84.65%, while those of the junior and senior radiologists were 56.82%, 56.82%, 56.95%, 56.62% and 64.20%, 64.20%, 64.35%, 64.11% respectively. With the help of CAD, the metrics of the junior and senior radiologists improved to 62.81%, 62.81%, 62.85%, 62.79% and 73.86%, 73.86%, 74.00%, 73.83%. The results almost repeated on the unbalanced dataset. The results show the proposed CAD approach can not only achieve better performance than radiologists, but also significantly improve the radiologists' diagnosis of FTC. The performances of the CAD system indicate it is a reliable reference for preoperative diagnosis of FTC, and might assist the development of a fast, accessible screening method for FTC.

Integrative Analysis of DNA Methylation and Gene Expression Identified Follicular Thyroid Cancer-Specific Diagnostic Biomarkers.

The diagnosis of follicular thyroid carcinoma (FTC) prior surgical resection remains a challenge, as routine screening methods, such as ultrasound or even FNAB, could not diagnose FTC preoperatively. Here, we performed an integrative analysis of DNA methylation and RNA array data from our own cohort (14 Follicular thyroid carcinoma vs 16 Benign thyroid lesion) to identify thyroid cancer-specific DNA methylation markers. We first identified differentially methylated and expressed genes and examined their correlations. Candidate DNA methylation sites were selected and further verified in validation set. Among all candidate methylation sites, cg06928209 was the most promising site as a molecular marker for early diagnosis, with a sensitivity of 90%, a specificity of 80% and an AUC of 0.77. Overall, our study demonstrates the potential use of methylation markers in FTC diagnosis and may boost the development of new epigenetic therapies.

Molecular Signature Expands the Landscape of Driver Negative Thyroid Cancers.

Simple SummaryThyroid cancer is the most common endocrine malignancy. However, the cytological diagnosis of certain malignant thyroid tumors and their benign counterparts is a challenge for preoperative diagnosis, as nearly 20–30% of biopsied thyroid nodules are classified as having an indeterminate risk of malignancy. Although multigene panels customized for thyroid cancer include most of the known tumor driver genes, many thyroid samples have negative results for the tested genes. To expand our knowledge, driver-negative samples were profiled by RNA-sequencing. Here, we report novel gene variants that might be associated with the pathogenesis of thyroid tumors, and show that driver-negative samples have two distinct expression signatures. We believe that our findings will ultimately impact preoperative diagnosis on thyroid nodules and provide directions for further experimental validation analysis.Thyroid cancer is the most common endocrine malignancy. However, the cytological diagnosis of follicular thyroid carcinoma (FTC), Hürthle cell carcinoma (HCC), and follicular variant of papillary thyroid carcinoma (FVPTC) and their benign counterparts is a challenge for preoperative diagnosis. Nearly 20–30% of biopsied thyroid nodules are classified as having indeterminate risk of malignancy and incur costs to the health care system. Based on that, 120 patients were screened for the main driver mutations previously described in thyroid cancer. Subsequently, 14 mutation-negative cases that are the main source of diagnostic errors (FTC, HCC, or FVPTC) underwent RNA-Sequencing analysis. Somatic variants in candidate driver genes (ECD, NUP98, LRP1B, NCOR1, ATM, SOS1, and SPOP) and fusions were described. NCOR1 and SPOP variants underwent validation. Moreover, expression profiling of driver-negative samples was compared to 16 BRAF V600E, RAS, or PAX8-PPARg positive samples. Negative samples were separated in two clusters, following the expression pattern of the RAS/PAX8-PPARg or BRAF V600E positive samples. Both negative groups showed distinct BRS, ERK, and TDS scores, tumor mutation burden, signaling pathways and immune cell profile. Altogether, here we report novel gene variants and describe cancer-related pathways that might impact preoperative diagnosis and provide insights into thyroid tumor biology.

Clinicopathological and metastasis status of follicular thyroid cancer

This study aims to evaluate the clinicopathological and metastasis status of follicular thyroid cancer at K Hospital. We conducted a retrospective combined with prospective cohort study of 48 follicular thyroid carcinoma patients treated by surgery at K hospital from January 2016 to July 2020. The mean age was 44±16.1 and the female/male ratio was 4.3/1. Most patients presented with an asymptomatic and had a unilateral tumor with mean diameter was 21.7±12 mm. 72.9% of tumors were classified as TIRADS 4 on ultrasound, and FNA did not play a big role in the diagnosis of follicular thyroid carcinoma with undetermined significance result in 48.9% of cases. Distant metastasis in 18.8%, the most common metastatic sites were bone, followed by the lungs. The overall rate of nodal metastasis was 31.3%. Cancer in both thyroid lobes had significantly associated with nodal metastasis (p<0.05)

Imaging the Human Thyroid Using Three-Dimensional Diffuse Optical Tomography: A Preliminary Study

Thyroid cancer is usually diagnosed by ultrasound imaging and fine-needle aspiration biopsy. However, diagnosis of follicular thyroid carcinomas (FTC) is difficult because FTC lacks nuclear atypia and a consensus on histological interpretation. Diffuse optical tomography (DOT) offers the potential to diagnose FTC because it can measure tumor hypoxia, while image reconstruction of the thyroid is still challenging mainly due to the complex anatomical features of the neck. In this study, we attempted to solve this issue by creating a finite element model of the human neck excluding the trachea (a void region). By reconstruction of the absorption coefficients at three wavelengths, 3D tissue oxygen saturation maps of the human thyroid are obtained for the first time by DOT.

An Evaluation of CD61 Immunohistochemistry in Identification of Vascular Invasion in Follicular Thyroid Neoplasms.

The identification of vascular invasion in follicular thyroid neoplasms is essential for categorizing lesions as benign (follicular adenomas) or malignant (follicular thyroid carcinomas). Among the histologic criteria diagnostic of true vascular invasion is tumor-cell associated thrombosis, including fibrin deposition and platelet clumping. This study aims to evaluate whether an immunohistochemical stain for the platelet-associated protein CD61 could assist in identifying tumor-associated thromboses and thereby confirm vascular invasion in follicular thyroid neoplasms. Histologic review and CD61 immunostaining of 19 atypical follicular adenomas, 13 non-metastatic follicular thyroid carcinomas, and 11 metastatic follicular thyroid carcinomas was performed. Linear arrays or clustered groups of CD61-expressing intravascular platelets were present in 51% of cases overall, including 54% of follicular thyroid carcinomas and 47% of follicular adenomas, mostly within intracapsular or peritumoral vessels. In three follicular thyroid carcinomas (all with distant metastases), CD61-expressing platelets were present in association with intravascular tumor cells. This finding was not present in adenomas. CD61 staining alone did not distinguish between atypical follicular adenomas, non-metastatic carcinomas, and metastatic carcinomas. When present in association with intravascular tumor cells, however, CD61-expressing platelets may serve as a marker for vascular invasion and aid in the diagnosis of follicular thyroid carcinoma.

Pituitary Metastasis of Thyroid Carcinoma: A Case Report

Patient: Male, 58Final Diagnosis: Pituitary metastais from thyroid carcinomaSymptoms: Visual acuity worseningMedication: —Clinical Procedure: NeurosurgerySpecialty: Endocrinology and MetabolicObjective:Rare diseaseBackground:Pituitary metastasis of thyroid carcinoma is a rare entity. Differential diagnosis with other lesions in the sellar/parasellar region, through clinical, histopathological, immunohistochemical, and imaging is challenging but essential for adequate treatment.Case Report:This case report describes a 58-year-old patient with the previous diagnosis of follicular thyroid carcinoma, with metastasis to cervical lymph nodes, bone, and lung, initially evolving to left palpebral ptosis. In the investigation, laboratory tests showed hypopituitarism, and magnetic resonance imaging of the skull showed a suprasellar formation measuring 2.2×3.5×2.5 cm, which increased in size in a few months. The patient underwent transcranial neurosurgery and subsequent immunohistochemical analysis, which confirmed pituitary metastasis of follicular thyroid carcinoma. The patient underwent chemotherapy and radiotherapy but died 26 months after the onset of symptoms.Conclusions:The differential diagnosis of pituitary metastasis from a benign lesion is difficult. Therefore, a careful analysis of the history and clinical evolution, use of complementary imaging tests, and, where possible, the histopathological and immunohistochemical analysis of the lesion for diagnostic elucidation are necessary.

Larger tumor size predicts nodal involvement in patients with follicular thyroid carcinoma.

Lymph node metastases are rare in patients with follicular thyroid carcinoma, with an average incidence of 5.5% of all cases reported in the literature. In the present study we focused on the search for risk factors predictive of lymph node involvement in patients with follicular thyroid carcinoma to plan the most appropriate management and follow-up. We carried out a cross-sectional study among patients with follicular thyroid carcinoma and lymph node metastasis at diagnosis and patients without lymph node involvement. From January 1998 to April 2008, 930 patients underwent thyroidectomy in our surgical department for a variety of thyroid disorders, 420 (45.2%) of them for a differentiated thyroid carcinoma. The medical records of 55 patients with histological diagnosis of follicular thyroid carcinoma were analyzed. Four patients (7.3%) had lymph node metastasis from follicular thyroid carcinoma at presentation in both the lateral and central neck compartments. Mean tumor size was significantly greater for follicular thyroid carcinomas with nodal metastasis (5.1 ± 1.4 cm) than for those without nodal involvement (3.0 ± 1.2 cm, P <0.010). Among factors supposed to influence the presence of nodal metastasis at diagnosis (age, gender, tumor size, multifocality, tumor poorly differentiated, tumor widely invasive, vascular invasion, thyroid capsular invasion, and extra thyroid invasion), tumor size larger than 4.0 cm was the only factor retained in the multivariate statistical model. Lymph node dissection must be planned only in the case of large follicular thyroid carcinomas. Since follicular carcinoma is usually diagnosed postoperatively, more attention should be paid to nodal involvement in the tumor re-staging during follow-up of those patients with tumors larger than 4.0 cm in diameter.

Preoperative cytological diagnosis of follicular thyroid carcinoma, is it possible?

Preoperative cytological diagnosis of follicular thyroid carcinoma, is it possible?

Follicular thyroid carcinoma but not adenoma recruits tumor-associated macrophages by releasing CCL15.

BackgroundThe differential diagnosis of follicular thyroid carcinoma (FTC) and follicular adenoma (FA) before surgery is a clinical challenge. Many efforts have been made but most focusing on tumor cells, while the roles of tumor associated macrophages (TAMs) remained unclear in FTC. Here we analyzed the differences between TAMs in FTC and those in FA.MethodsWe first analyzed the density of TAMs by CD68 immunostaining in 59 histologically confirmed FTCs and 47 FAs. Cytokines produced by FTC and FA were profiled using antibody array, and validated by quantitative PCR. Chemotaxis of monocyte THP-1 was induced by condition medium of FTC cell lines (FTC133 and WRO82-1) with and without anti-CCL15 neutralizing antibody. Finally, we analyzed CCL15 protein level in FTC and FA by immunohistochemistry.ResultsThe average density of CD68+ cells was 9.5 ± 5.4/field in FTC, significantly higher than that in FA (4.9 ± 3.4/field, p < 0.001). Subsequently profiling showed that CCL15 was the most abundant chemokine in FTC compared with FA. CCL15 mRNA in FTC was 51.4-folds of that in FA. CM of FTC cell lines induced THP-1 cell chemotaxis by 33 ~ 77 %, and anti-CCL15 neutralizing antibody reduced THP-1 cell migration in a dose-dependent manner. Moreover, we observed positive CCL15 immunostaining in 67.8 % of FTCs compared with 23.4 % of FAs.ConclusionOur study suggested FTC might induce TAMs infiltration by producing CCL15. Measurement of TAMs and CCL15 in follicular thyroid lesions may be applied clinically to differentiate FTC from FA pre-operation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2114-7) contains supplementary material, which is available to authorized users.

Extending the Impact of RAC1b Overexpression to Follicular Thyroid Carcinomas.

RAC1b is a hyperactive variant of the small GTPase RAC1 known to be a relevant molecular player in different cancers. Previous studies from our group lead to the evidence that its overexpression in papillary thyroid carcinoma (PTC) is associated with an unfavorable prognosis. In the present study, we intended to extend the analysis of RAC1b expression to thyroid follicular neoplasms and to seek for clinical correlations. RAC1b expression levels were determined by RT-qPCR in thyroid follicular tumor samples comprising 23 follicular thyroid carcinomas (FTCs) and 33 follicular thyroid adenomas (FTAs). RAC1b was found to be overexpressed in 33% of carcinomas while no RAC1b overexpression was documented among follicular adenomas. Patients with a diagnosis of FTC were divided into two groups based on longitudinal evolution and final outcome. RAC1b overexpression was significantly associated with both the presence of distant metastases (P = 0.01) and poorer clinical outcome (P = 0.01) suggesting that, similarly to that previously found in PTCs, RAC1b overexpression in FTCs is also associated with worse outcomes. Furthermore, the absence of RAC1b overexpression in follicular adenomas hints its potential as a molecular marker likely to contribute, in conjunction with other putative markers, to the preoperative differential diagnosis of thyroid follicular lesions.

The Diagnostic Usefulness of HMGA2, Survivin, CEACAM6, and SFN/14-3-3 δ in Follicular Thyroid Carcinoma.

Background:Follicular thyroid carcinoma (FTC) is the second most common thyroid malignancy and its differential diagnosis includes follicular adenoma (FA) and adenomatous goiter (AG). Several ancillary markers have been suggested to aid in the diagnosis of FTC, but the successful use of these methods still needs to be validated.Methods:In the present study, we verified the immunoexpression of HMGA2, CEACAM6, survivin, and SFN/14-3-3 δ in lesions including 41 AGs, 72 FAs, and 79 FTCs. We evaluated their diagnostic usefulness, combined with galectin 3, Hector Battifora mesothelial 1 (HBME1), cytokeratin 19, and cyclin D1, in diagnosing FTC.Results:The expressions of HBME1 (65.8%) and HMGA2 (55.7%) were significantly higher in FTCs than in FAs and AGs (p<.001 and p=.005, respectively). HBME1 was the only marker that was more frequently expressed in FTCs than in FAs (p=.021) and it was more frequently expressed in follicular neoplasms than in AGs (p<.001). Among the novel markers, the combination of HMGA2 and HBME1 showed the highest sensitivity (72.2%) and specificity (76.1%) for diagnosing FTC. CEACAM6, survivin, and SFN/14-3-3 δ were barely expressed in most cases.Conclusions:Our present results show that only HMGA2 can be beneficial in differentiating FTC using the novel markers.

Molecular differential diagnosis of follicular thyroid carcinoma and adenoma based on gene expression profiling by using formalin-fixed paraffin-embedded tissues

BackgroundDifferential diagnosis between malignant follicular thyroid cancer (FTC) and benign follicular thyroid adenoma (FTA) is a great challenge for even an experienced pathologist and requires special effort. Molecular markers may potentially support a differential diagnosis between FTC and FTA in postoperative specimens. The purpose of this study was to derive molecular support for differential post-operative diagnosis, in the form of a simple multigene mRNA-based classifier that would differentiate between FTC and FTA tissue samples.MethodsA molecular classifier was created based on a combined analysis of two microarray datasets (using 66 thyroid samples). The performance of the classifier was assessed using an independent dataset comprising 71 formalin-fixed paraffin-embedded (FFPE) samples (31 FTC and 40 FTA), which were analysed by quantitative real-time PCR (qPCR). In addition, three other microarray datasets (62 samples) were used to confirm the utility of the classifier.ResultsFive of 8 genes selected from training datasets (ELMO1, EMCN, ITIH5, KCNAB1, SLCO2A1) were amplified by qPCR in FFPE material from an independent sample set. Three other genes did not amplify in FFPE material, probably due to low abundance. All 5 analysed genes were downregulated in FTC compared to FTA. The sensitivity and specificity of the 5-gene classifier tested on the FFPE dataset were 71% and 72%, respectively.ConclusionsThe proposed approach could support histopathological examination: 5-gene classifier may aid in molecular discrimination between FTC and FTA in FFPE material.

Molecular Photoacoustic Imaging of Follicular Thyroid Carcinoma

To evaluate the potential of targeted photoacoustic imaging as a noninvasive method for detection of follicular thyroid carcinoma. We determined the presence and activity of two members of matrix metalloproteinase family (MMP), MMP-2 and MMP-9, suggested as biomarkers for malignant thyroid lesions, in FTC133 thyroid tumors subcutaneously implanted in nude mice. The imaging agent used to visualize tumors was MMP-activatable photoacoustic probe, Alexa750-CXeeeeXPLGLAGrrrrrXK-BHQ3. Cleavage of the MMP-activatable agent was imaged after intratumoral and intravenous injections in living mice optically, observing the increase in Alexa750 fluorescence, and photoacoustically, using a dual-wavelength imaging method. Active forms of both MMP-2 and MMP-9 enzymes were found in FTC133 tumor homogenates, with MMP-9 detected in greater amounts. The molecular imaging agent was determined to be activated by both enzymes in vitro, with MMP-9 being more efficient in this regard. Both optical and photoacoustic imaging showed significantly higher signal in tumors of mice injected with the active agent than in tumors injected with the control, nonactivatable, agent. With the combination of high spatial resolution and signal specificity, targeted photoacoustic imaging holds great promise as a noninvasive method for early diagnosis of follicular thyroid carcinomas.

Trefoil Factor 3 (TFF3) mRNA Expression Level in Follicular Thyroid Tumors Using Formalin-Fixed, Paraffin-Embedded (FFPE) Blocks

Background: Differential diagnosis of follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA) is often difficult since presence or absence of capsular/vascular invasion can not be determined by preoperative fine needle aspiration cytology, and may not be judged unanimously on permanent sections even among experienced pathologists. Determination of molecular-genetic factors such as trefoil factor 3 (TFF3) mRNA in the follicular thyroid tumors may be useful aid to improve the accuracy of diagnosis, though it is considered to be unstable and relatively low concentrated genetic substance. Purpose of our study is to investigate expression level of TFF3 mRNA of thyroid follicular tumors using formalin-fixed, paraffin-embedded (FFPE) tissue. Methods: Study population included FFPE sections from 19 FTC cases, 20 FTA cases, 11 adenomatous goiter (G) cases and 12 samples of normal thyroid tissue (N) adjacent to thyroid tumors. RNeasy FFPE kit was used for extraction of total RNA. Purification and concentration values were determined by spectrophotometer. Extracted RNA was used for cDNA synthesis in reverse transcription. Synthesized cDNA subsequently proceeded for relative quantification of TFF3 mRNA by RT-qPCR using TFF3 primers. Glyceroldehyde-3-phosphate dehydrogenase (GAPDH) and hypoxanthin phosphorobosyltransferase1 (HPRT1) were used as control genes. The mean and standard deviation of TFF3 mRNA expression level were analyzed by software Multiplate RQ. Results: Extraction by the FFPE kit yielded high concentration of RNA in all cases. Purification values were 1.8 in average. Concentration values were significantly higher in FTC and FTA relative to G and N tissues, possibly due to high density of thyrocytes in the samples. Relative quantification of TFF3 mRNA expression level showed broad ranges both in FTC and FTA, while the analyses in G and N tissues indicated narrow ranges. Conclusion: FFPE tissues from thyroid follicular tumors can be used for measurement of unstable and low concentrated genetic substances such as TFF3 mRNA. Its diagnostic value yet remains to be determined.

Diagnostic accuracy of fine needle aspiration biopsy cytology and ultrasonography in patients with thyroid nodules diagnosed as benign or indeterminate before thyroidectomy

Fine-needle aspiration biopsy cytology (FNABC) and ultrasonography (US) play an important role in differentiating benign thyroid nodules from malignant nodules. We retrospectively investigated the prevalence of follicular thyroid carcinoma (FTC) in patients with thyroid nodules whose FNABC and US readings were not malignant before thyroidectomy. Between 2007 and 2008, 3333 patients underwent thyroidectomy at our institution, and the 737 of them who had thyroid nodule that had been diagnosed as hyperplastic nodule or follicular tumor by FNABC and US preoperatively were the subjects in this study. Postoperative histopathology showed hyperplastic nodule in 416 patients, follicular adenoma in 200 patients, FTC in 99 patients, and other disease in 22 patients. By FNABC, 34 (6.7%) of the 505 patients with diagnosis as benign and 65 (28%) of the 232 patients with diagnosis as indeterminate, were diagnosed as having FTC. The diagnosis was FTC in 56 (9.6%) of the 582 patients with a preoperative diagnosis of hyperplastic nodule by US and 43 (27.7%) of the 155 patients with a diagnosis of follicular tumor by US. The diagnosis of FTC was made in 21 (4.8%) of 438 patients who were concurrently diagnosed as benign by FNABC and as hyperplastic nodule by US, and in 30 (34.1%) of 88 patients who were diagnosed as indeterminate by FNABC and follicular tumor by US. FNABC has been the mainstay for the preoperative evaluation of thyroid nodule. The results of this study showed that US can also be a useful tool for diagnosing FTC.