Papillary Thyroid Carcinoma Lymph Node Research Articles

Application of selective neck lymphadenectomy in papillary thyroid carcinoma

Objective To explore the rule of papillary thyroid carcinoma lymph node metastasis,and provide the basis for cervical lymph node dissection in papillary thyroid carcinoma selective node.Methods The clinical data and follow-up results of 50 cases with thyroid papillary carcinoma were retrospectively analyzed.Results Average number of selective neck dissection was 4.2 cases,lymph node metastasis in 19 cases (38.0％),6 cases had postoperative complications(12.0％).The patients were followed-up for 4 years without recurrence or metastasis of thyroid cancer.4 cases during the follow-up period appeared neck lymph node metastasis,accounted for 8.0％.Conclusion Primary radical combined with selective neck dissection is an effective procedure for the treatment of Ⅰ,Ⅱ stage of thyroid papillary carcinoma. Key words: Lymph node excision; Thyroid neoplasms

Combined staining for immunohistochemical markers in the diagnosis of papillary thyroid carcinoma: Improvement in the sensitivity or specificity?

To investigate the ability of cytokeratin (CK)-19, galectin-3, human bone marrow endothelial cell (HBME)-1 and tyrosine kinase-type cell surface receptor HER2 (HER-2/neu) to differentiate papillary thyroid carcinoma (PTC) from benign thyroid nodules. Archival specimens of PTC and benign thyroid nodules were included in this retrospective immunohistochemical study. CK-19, galectin-3, HBME-1, and HER-2/neu protein levels were analysed immunohistochemically using routinely prepared tissue sections. Specimens from 331 patients with PTC and 664 patients with benign thyroid nodules were reviewed. For all four protein markers, the percentage of samples with cells that demonstrated positive immunostaining was significantly higher in PTC specimens than in benign thyroid nodules. As a single protein marker, CK-19 was the most sensitive (92.7%) and HBME-1 was the most specific (97.9%). The combination of CK-19 and galectin-3 was the most sensitive (82.8%), and the combinations of HBME-1 with CK-19 or galectin-3 or HER-2/neu were the most specific (98.3%). The combination of HBME-1 and either CK19 or galectin-3 or HER-2/neu can improve the specificity of the diagnosis of PTC.

The Wnt/β-catenin pathway drives increased cyclin D1 levels in lymph node metastasis in papillary thyroid cancer

We examined the expression of cyclin D1 in conjunction with β-catenin and the phosphorylated inactive form of glycogen synthase kinase 3β (GSK-3β) in benign, nonneoplastic thyroid tissue as well as papillary thyroid carcinoma primary tumors and nodal metastases. We aim to unravel the regulation of cyclin D1 and determine if this cell cycle protein is a useful biomarker for metastatic disease. It is clear that expression of cyclin D1 (P < .0001), β-catenin (P < .0001), and inactive form of GSK-3β (P < .0001) are significantly higher in papillary thyroid carcinoma primary tumors than in corresponding benign, nonneoplastic tissue thyroid specimens. Interestingly, β-catenin and cyclin D1 expressions in papillary thyroid carcinoma are correlated (P = .025), implying that β-catenin is a factor driving higher levels of cyclin D1 consistent with previous cell models linking Wnt/β-catenin signaling and cyclin D1 expression. Conversely, inactive form of GSK-3β expression does not correlate with cyclin D1 (P = .52) or β-catenin expression (P = .54). We also did not observe any relationship between tumor size and marker expression. Comparing papillary thyroid carcinoma primary tumors with or without nodal metastases, we did not see any differences in expression of inactive form of GSK-3β (P = .95), β-catenin (P = .14), or cyclin D1 (P = .46). However, in papillary thyroid carcinoma lymph node specimens, the up-regulation of cyclin D1 (P = .0083) was highly significant compared with primary tumors. pGSK-3β and β-catenin expression did not vary between primary tumors and nodal specimens. In conclusion, we have demonstrated that expression of cyclin D1 is linked to nodal metastases and that cyclin D1 levels are regulated by Wnt/β-catenin signaling. GSK pathway-mediated regulation of β-catenin or cyclin D1 expression does not appear operative in papillary thyroid carcinoma.

BRAFV600E mutation, TIMP-1 upregulation, and NF-κB activation: closing the loop on the papillary thyroid cancer trilogy

BRAF(V600E) is the most common mutation found in papillary thyroid carcinoma (PTC). Tissue inhibitor of metalloproteinases (TIMP-1) and nuclear factor (NF)-κB have been shown to play an important role in thyroid cancer. In particular, TIMP-1 binds its receptor CD63 on cell surface membrane and activates Akt signaling pathway, which is eventually responsible for its anti-apoptotic activity. The aim of our study was to evaluate whether interplay among these three factors exists and exerts a functional role in PTCs. To this purpose, 56 PTC specimens were analyzed for BRAF(V600E) mutation, TIMP-1 expression, and NF-κB activation. We found that BRAF(V600E) mutation occurs selectively in PTC nodules and is associated with hyperactivation of NF-κB and upregulation of both TIMP-1 and its receptor CD63. To assess the functional relationship among these factors, we first silenced BRAF gene in BCPAP cells, harboring BRAF(V600E) mutation. We found that silencing causes a marked decrease in TIMP-1 expression and NF-κB binding activity, as well as decreased invasiveness. After treatment with specific inhibitors of MAPK pathway, we found that only sorafenib was able to increase IκB-α and reduce both TIMP-1 expression and Akt phosphorylation in BCPAP cells, indicating that BRAF(V600E) activates NF-κB and this pathway is MEK-independent. Taken together, our findings demonstrate that BRAF(V600E) causes upregulation of TIMP-1 via NF-κB. TIMP-1 binds then its surface receptor CD63, leading eventually to Akt activation, which in turn confers antiapoptotic behavior and promotion of cell invasion. The recognition of this functional trilogy provides insight on how BRAF(V600E) determines cancer initiation, progression, and invasiveness in PTC, also identifying new therapeutic targets for the treatment of highly aggressive forms.

The preeminence of growth pattern and invasiveness and the limited influence of BRAF and RAS mutations in the occurrence of papillary thyroid carcinoma lymph node metastases

Prognostic factors indicative of papillary thyroid carcinoma (PTC) aggressive behaviour remain incompletely established partially due to the different composition of the series on record regarding the relative proportion of classic PTC (CPTC) and follicular variant PTC (FVPTC) subtypes. Several clinico-morphological features of PTC, together with the occurrence of BRAF mutations, are still not fully accepted as markers of aggressiveness. In the present clinico-pathological study of a series of 75 CPTC and FVPTC cases, we evaluated the relative contribution of the morphological features of the tumours and their BRAF and N-RAS status for the occurrence of nodal metastases. The morphological features most closely related to the occurrence of nodal metastases were extra-thyroid extension and poorly circumscribed growth pattern, in both CPTC and FVPTC. Additional features significantly associated to nodal metastases were multicentricity in the CPTC and vascular invasion in the FVPTC group. BRAF V600E mutation was detected in 29% of tumours, 41% of CPTC and 16% of FVPTC; N-RAS Q61R mutation was detected in 6% of tumours, 3% of CPTC and 10% of FVPTC. BRAF mutation was significantly more frequent in the CPTC group and in females, and it was detected only in patients older than 20years, suggesting a late tumourigenic effect in the development of PTC. BRAF mutation was not significantly associated to any of the other studied features related to aggressiveness or nodal metastases. These results highlight the importance of infiltrative growth pattern and invasiveness over the presence of BRAF mutation in classic and follicular variant PTC for the development of nodal metastases.

Abstract 5219: The LIM protein LIMD2 functions as an effector and biomarker for metastasis in multiple tumor types

Abstract The LIM domain is found in proteins from a wide variety of eukaryotic organisms. The LIM domain is organized as a tandem zinc-finger structure that functions as a modular protein-binding interface. LIM domain containing proteins have diverse cellular roles such as regulators of gene expression, cytoarchitecture, cell adhesion, cell motility, signal transduction, and biosensors. LIMD2 belongs to the LIM only family of LIM proteins and was identified as a biomarker for papillary thyroid carcinoma lymph node metastasis from molecular profiling of matched samples. However, the biological function of LIMD2 remains unknown. To identify whether LIMD2 is a biomarker for other cancers, highly specific LIMD2 polyclonal and monoclonal antibodies were developed and several cancer cell lines were tested for LIMD2 expression. These cancer cell lines were derived from breast cancer, melanoma, bladder cancer, and thyroid cancer. We found that the cancer cell lines derived from more aggressive tumors exhibited higher levels of LIMD2 protein expression. Furthermore, cells expressing higher levels of LIMD2 had increased migratory capabilities. Over-expression of LIMD2 protein in the less aggressive bladder cancer cell line (RT4) showed an increase in migration and colony formation ability. Conversely, knockdown of LIMD2 using siRNA decreased the migratory ability of the malignant melanoma cancer cell line and caused morphological changes in these cells. These data not only underscore the importance of LIMD2 as a key metastatic biomarker, but also suggest that LIMD2 may play a functional role in tumorgenicity. LIMD2 may also serve as a novel anti-metastatic target to improve the efficacy of conventional cancer therapeutics. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5219. doi:10.1158/1538-7445.AM2011-5219

Serum vascular endothelial growth factor-D levels correlate with cervical lymph node metastases in papillary thyroid carcinoma

The aim of this multicenter study was to evaluate the clinical relevance of serum vascular endothelial growth factor-D (VEGF-D) in papillary thyroid carcinoma (PTC). This prospective study consisted of 74 patients with primary PTC and 15 patients with benign thyroid nodules treated from 2008 to 2009. VEGF-D concentration was compared with patient clinicopathologic features and lymph node metastases. There was no significant difference in mean serum VEGF-D levels between the PTC and benign thyroid nodule groups. Within the PTC group, serum VEGF-D levels were significantly higher in patients with lymph node metastases than in patients without metastases (241.92 vs. 213.89 pg/ml, respectively; P = 0.035). Receiver operating characteristic curve analysis revealed that preoperative serum VEGF-D levels were predictive of lymph node metastases in the patients >45 years. Serum VEGF-D level that was correlated with the presence of cervical lymph node metastases in PTC patients might be a useful prognostic indicator.

甲状腺乳頭癌嚢胞性頸部リンパ節転移の鑑別診断―穿刺液中サイログロブリン測定の有用性―

Combining ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI) and fine-needle aspiration cytology (FNAC) usually results in the best preoperative diagnosis of cervical masses, including neoplasms. This may not be true, however, especially in occult papillary thyroid carcinoma (PTC) associated with single cystic cervical lymph node metastasis. We assessed the role of thyroglobulin measurement in FNA fluid (FNATg) in differentially diagnosing cystic cervical mass lesions, including PTC cystic lymph node metastasis. We reviewed the records of 17 subjects with cervical cystic masses undergoing both FNATg measurement and surgery. FNA was done under ultrasonographic guidance. We also measured FNATg concentrations from extrathyroid lesions, consisting of cystic cervical lymph node metastases and benign cystic lesions. Pathological diagnosis involved 5 PTC lymph node metastases, 3 lateral cervical cysts, 7 thyroglossal duct cysts, and 2 squamous cell carcinoma (lung and oropharynx) lymph node metastases. FNATg of PTC lymph node metastasis was much higher than the reference range of blood serum thyroglobulin, although much lower for the lateral cervical cyst detection threshold. FNAC and FNATg measurement are thought to be mutually complementary in the differential diagnosis of PTC cystic lymph node metastasis. High concentrations of FNATg in a cystic cervical mass is considered specific to PTC lymph node metastasis, indicating its usefulness in distinguish PTC cystic metastasis from other cystic lesions. Including FNATg measurement with FNAC may thus improve preoperative diagnosis accuracy without additionally stressing subjects with PTC cystic lymph node metastasis.

Paired box gene 8, HBME‐1, and cytokeratin 19 expression in preoperative fine‐needle aspiration of papillary thyroid carcinoma

Paired box gene 8 (PAX8), a member of the thyroid-specific transcription factors, has recently been investigated as a useful marker of thyroid epithelial neoplasms. To the authors' knowledge, its utility in the immunohistochemistry of papillary thyroid carcinoma (PTC) has not been well studied to date. The goal of the current study was to compare the immunohistochemical expression of PAX8 with HBME-1 and cytokeratin 19 (CK19) expression on cell block preparations of PTC and benign thyroid nodules (BTN). Thirty-two cases of PTC and 20 cases of BTN diagnosed on fine-needle aspiration were included. The cell blocks were immunohistochemically stained for PAX8, HBME-1, and CK19. PAX8 demonstrated nuclear positivity in >90% of cases with PTC (31 of 32 cases; 96.9%) and BTN (20 of 20 cases; 100%), with a high sensitivity (0.97), but low specificity (0). HBME-1 and CK19 were found to have high sensitivity (0.78 and 0.75, respectively) and specificity (0.95 for both) for PTC. Statistically significant differences in staining intensity and distribution were noted for the PAX8 antibody (negative [1 of 32 cases] to weakly positive [20 of 32 cases] in 65.6% of PAX8-positive PTCs, and intermediate to strong in 100% of BTNs). In contrast to PAX8, HBME-1 and CK19 were found to have a high degree of both sensitivity and specificity for PTC. The results of the current study demonstrate that strong PAX8 staining appears to be typical of BTNs, whereas negative to weakly positive staining is noted in PTC. PAX8, HMBE-1 and CK19 may all play a role, particularly as a panel; however, the interpretation of PAX8 should consider the intensity and distribution of staining.

A valuable adjunct to FNA diagnosis of papillary thyroid carcinoma: In-house PCR assay for BRAF T1799A (V600E)

The diagnostic approach to thyroid nodules generally starts with FNA cytology. However, approximately one-fifth of cytologic evaluations yield indeterminate cytological findings but only 20% of cases with indeterminate thyroid nodule cytology have a cancer diagnosis, emphasizing the need for an effective ancillary test based on FNA material to help prevent unnecessary surgery. Detection of BRAFV600E mutation, the genetic signature of papillary thyroid carcinoma (PTC) in FNA material provides an invaluable diagnostic adjunct to overcome the limitations of FNA cytology. There are many ways to detect V600E, such as direct DNA sequencing, allele-specific PCR and hybridization-based colorimetric methods. In this study, a newer simple PCR method is presented that removes requirements for sequencing special equipment and commercial kits. Two forward primers including the mutant sequence specific (F2), and one common reverse (R) primer were optimized to generate a 241 bp fragment (F1R), an internal PCR control, and a 141 bp fragment (F2R) denoting the presence of V600E. Sensitivity studies revealed that the assay is capable of detecting V600E even in 1 ng of DNA. Direct sequencing data of 241 bp F1R fragment proved the specificity of the assay. For validation studies of the sequence specific multiplex PCR assay, archival FNA slides were used in a group of thyroid lesions including PTC, follicular carcinoma, follicular adenoma, Hashimoto thyroiditis, and benign thyroid nodules. The newer PCR-based method presented in this study is a practical, inexpensive one-step assay to detect the BRAF T1796A mutation on FNA samples.

Clinical Risk Factors Associated with Cervical Lymph Node Recurrence in Papillary Thyroid Carcinoma

Recurrence of regional cervical lymph nodes in patients with papillary thyroid carcinoma (PTC) is not uncommon, and is an important factor affecting the quality of life. The aims of this study are to investigate the risk factors that are associated with regional lymph node recurrence by comparing a group of patients with regional lymph node recurrence with a group without lymph node recurrence, and to analyze the clinical characteristics of recurrent regional lymph nodes in PTC. A retrospective analysis was performed on 189 patients who underwent surgery for PTC. By comparing a group with recurrent cervical lymph nodes (n = 33) with a group without recurrent cervical lymph nodes (n = 156), the risk factors for cervical lymph node recurrence were investigated and the clinical characteristics of recurrent cervical lymph nodes were analyzed. Tumor size >2 cm, presence of extrathyroid tumor spread, high T stage, and presence of lymph node metastasis were associated with regional lymph node recurrence in univariate analysis (p < 0.05). Among them, only the N stage was significantly associated with regional recurrence in multivariate analysis (p < 0.05). The disease-free survival period was shorter in the lymph node metastasis-positive group, and the 10-year disease-free survival rate was 77.8% in the lymph node metastasis-negative group and 57.9% in the lymph node metastasis-positive group (p < 0.05). Among 130 patients without lymph node metastasis, regional recurrence occurred in 13 patients (10%), and the frequent levels of regional recurrence were levels II-IV of ipsilateral neck. In the patients with lymph node metastasis, the frequent levels were levels IV-VI of ipsilateral side and level II of the contralateral side. Considering the low incidence of regional lymph node recurrence and the levels with frequent regional recurrence in patients without lymph node metastasis, elective neck dissection in all cases of total thyroidectomy may be immoderate. However, if any risk factors for regional recurrence, including large tumor size, presence of extrathyroid spread, high T stage, and presence of lymph node metastasis, are detected by preoperative and intraoperative evaluation, a systematic compartment-oriented lymphadenectomy should be considered because of the high possibility of regional recurrence.

Ultrasonographic Findings of Medullary Thyroid Carcinoma: a Comparison with Papillary Thyroid Carcinoma

ObjectiveThis study was designed to evaluate the ultrasonographic (US) findings of medullary thyroid carcinoma (MTC) as compared to findings for papillary thyroid carcinoma (PTC).Materials and MethodsThe study included 21 cases of MTC that were surgically diagnosed between 2002 and 2007 and 114 cases of PTC that were diagnosed in 2007. Two radiologists reached a consensus in the evaluation of the US findings. The US findings were classified as recommended by the Thyroid Study Group of the Korean Society of Neuroradiology and Head and Neck Radiology (KSNHNR) and each nodule was identified as suspicious malignant, indeterminate or probably benign. The findings of medullary and papillary carcinomas were compared with use of the chi-squared test.ResultsThe common US findings for MTCs were solid internal content (91%), an ovoid to round shape (57%), marked hypoechogenicity (52%) and calcifications (52%). Among the 21 cases of MTC nodules, 17 (81%) were classified as suspicious malignant nodules. The mean size (longest diameter) of MTC nodules was 19 ± 13.9 mm and the mean size (longest diameter) of PTC nodules was 11 ± 7.4 mm; this difference was statistically significant (p < 0.05). An ovoid to round shape was more prevalent for MTC lesions than for PTC lesions (p < 0.05).ConclusionThe US criteria for suspicious malignant nodules as recommended by the Thyroid Study Group of the KSNHNR correspond to most MTC cases. The US findings for MTC are not greatly different from PTC except for the prevalence of an ovoid to round shape.

Gene Expression Profiling of Papillary Thyroid Carcinoma Identifies Transcripts Correlated with BRAF Mutational Status and Lymph Node Metastasis

To identify papillary thyroid carcinoma (PTC)-associated transcripts, we compared the gene expression profiles of three Serial Analysis of Gene Expression libraries generated from thyroid tumors and a normal thyroid tissue. Selected transcripts were validated in a panel of 57 thyroid tumors using quantitative PCR (qPCR). An independent set of 71 paraffin-embedded sections was used for validation using immunohistochemical analysis. To determine if PTC-associated gene expression could predict lymph node involvement, a separate cohort of 130 primary PTC (54 metastatic and 76 nonmetastatic) was investigated. The BRAF(V600E) mutational status was compared with qPCR data to identify genes that might be regulated by abnormal BRAF/MEK/extracellular signal-regulated kinase signaling. We identified and validated new PTC-associated transcripts. Three genes (CST6, CXCL14, and DHRS3) are strongly associated with PTC. Immunohistochemical analysis of CXCL14 confirmed the qPCR data and showed protein expression in PTC epithelial cells. We also observed that CST6, CXCL14, DHRS3, and SPP1 were associated with PTC lymph node metastasis, with CST6, CXCL14, and SPP1 being positively correlated with metastasis and DHRS3 being negatively correlated. Finally, we found a strong correlation between CST6 and CXCL14 expression and BRAF(V600E) mutational status, suggesting that these genes may be induced subsequently to BRAF activation and therefore may be downstream in the BRAF/MEK/extracellular signal-regulated kinase signaling pathway. CST6, CXCL14, DHRS3, and SPP1 may play a role in PTC pathogenesis and progression and are possible molecular targets for PTC therapy.

Molecular Profiling of Matched Samples Identifies Biomarkers of Papillary Thyroid Carcinoma Lymph Node Metastasis

Biomarkers of papillary thyroid carcinoma (PTC) metastasis can accurately identify metastatic cells and aggressive tumor behavior. To find new markers, serial analysis of gene expression (SAGE) was done on three samples from the same patient: normal thyroid tissue, primary PTC, and a PTC lymph node metastasis. This genomewide expression analysis identified 31 genes expressed in lymph node metastasis, but not in the primary tumor. Eleven genes were evaluated by quantitative real-time reverse transcription-PCR (qPCR) on independent sets of matched samples to find genes that were consistently different between the tumor and metastatic samples. LIMD2 and PTPRC (CD45) showed a statistically significant difference in expression between tumor and metastatic samples (P < 0.0045), and an additional gene (LTB) had borderline significance. PTPRC and LTB were tested by immunohistochemistry in an independent set of paired samples, with both markers showing a difference in protein expression. All 20 metastases from 6 patients showed expression in both markers, with little or no expression in primary tumor. Some of these markers could provide an improved means to detect metastatic PTC cells during initial staging of a newly diagnosed carcinoma and/or to rule out recurrence. The functional role of these genes may also provide insight into mechanisms of thyroid cancer metastasis.

The Clinical Significance of Retinoic Acid Receptor β Expressions in Primary and Recurred Metastatic Lymph Node Papillary Thyroid Carcinomas

Background: The present study was designed to investigate the correlations of retinoic acid receptor β (RARβ) expression for primary and recurred metastatic lymph node (LN) papillary thyroid carcinoma (PTC) tissues and the correlations of RARβ expression with the uptake of I131 as detected on a whole body scan (WBS). Methods: Primary and metastatic LN PTC tissues were examined by immunohistochemical methods. Staining positivity was calculated, and staining intensity was graded as negative (0), weak (1+), moderate (2+) and strong (3+). Nuclear staining intensity (NSI) of cells from tissues was also examined. Results: Seventeen patients who had regional cervical LN metastasis without distant metastasis were included in the study, and 13 patients had the abnormal uptake of I131 as detected on a WBS. In primary PTC tissues, RARβ staining positivity and intensity of carcinoma cells were significantly higher than those of normal cells but NSI was significantly higher in normal cells than carcinoma cells. Between primary and metastatic LN PTC tissues, RARβ staining intensity was correlated after controlling for age. Primary PTC tissues from 14 (82.4%) out of 17 patients were concordant between NSI and the uptake of I131 as detected on a WBS. NSI predicted the I131 uptake as detected on a WBS with 81.3% positive predicted value (PPV) and 100% negative predicted value. Metastatic LN PTC tissues from 13 (76.5%) out of 17 patients were concordant between NSI and the uptake of I131 as detected on a WBS. NSI predicted the uptake of I131 as detected on a WBS with 76.5% PPV. When the results of NSI taken either as positive or negative were correlated with those of the uptake of I131 as detected on a WBS in primary and metastatic LN PTC tissues, the correlation was not significant after controlling for age. Conclusion: Our results demonstrate that nuclear RARβ expression may be decreased in PTC tissues than normal thyroid tissues, and RARβ expression in primary PTC tissues as well as in recurred metastatic LN PTC tissues may predict the uptake of I131 as detected on a WBS.

Relationship of sodium/iodide symporter expression with I131 whole body scan uptake between primary and metastatic lymph node papillary thyroid carcinomas

The aim of the present study was to evaluate total and membranous Na+/I- symporter (NIS) expressions in papillary thyroid carcinoma (PTC) tissue, correlation of NIS expression between primary and metastatic lymph node (LN) PTC tissues, and relationship of NIS expression with I131 whole body scan (WBS) uptake between primary and metastatic LN PTC tissues by analyzing 17 pairs of primary and metastatic LN PTC tissues. Staining positivity was calculated, and staining intensity was graded as negative (0), weak (1+), moderate (2+) and strong (3+). In primary PTC tissues, positivities and intensities of normal cells were higher than those of carcinoma cells but had no correlation with those in matched metastatic LN PTC tissues. In classic type, positivities, intensities and membranous intensities (mIS) were correlated between primary and matched metastatic LN PTC tissues. In patients aged younger than 45 yr, positivities and intensities in primary PTC tissues had correlation with those in matched metastatic LN PTC tissues. Positivities, intensities, mIS and pathological subtype of carcinoma cells in primary PTC tissues were not correlated with age, tumor size, TNM stage, MACIS score and thyroglobulin (Tg) levels at the time of I131 WBS. Sensitivity, specificity, as well as positive and negative predicted values of mIS in patients with I131 WBS uptake were 69.2, 75, 90 and 42.9% in primary PTC tissues, and 92.3, 100, 100 and 80% in metastatic LN PTC tissues. The results of mIS taken either as positive or negative were correlated with those of I131 WBS after controlling for age. Our results demonstrate that PTC tissues have altered total and membranous NIS expressions, suggesting that NIS expression in primary PTC tissues may predict NIS expression and I131 WBS uptake in matched metastatic LN PTC tissues.

Tc-99m depreotide imaging of I-131-negative recurrent metastatic papillary thyroid carcinoma

The detection of radioiodine (I-131)-negative metastases of differentiated thyroid carcinoma (DTC) has been hitherto successfully tried by the well-known synthetic somatostatin analogue indium-111-labeled DTPA-octreotide (In-111 pentetreotide). The objective of this study was to evaluate the usefulness of scintiscan with the newer synthetic somatostatin analogue Tc-99m depreotide, in the restaging of papillary thyroid carcinoma (PTC) with detectable serum thyroglobulin (Tg) levels and negative I-131 whole-body scan (WBS). Whole-body planar and cervico-thoracic tomographic scintigraphy (single-photon emission tomography-SPET) with Tc-99m depreotide was performed in a 68-year-old male patient suffering from PTC stage III, with a mild increase in serum Tg levels coupled with a recent negative I-131 WBS. The findings were compared with those of neck ultrasonography (US) and computerized tomography (CT). Nodal neck dissection and histopathology provided the definitive diagnosis. Tc-99m depreotide scanning revealed foci of cervical lymph node metastases, which did not accumulate I-131. The findings were in accordance with neck US and CT. Histopathology established the diagnosis of metastatic cervical lymph node PTC. Lymph node immunoreactivity was positive for the somatostatin receptor subtypes 2, 5 and 3. Scintigraphy with Tc-99m depreotide could prove a useful adjunct to the armamentarium for the follow-up of PTC, especially in the setting of detectable serum Tg and negative I-131 WBS.

Clonal origin of non-medullary thyroid tumours assessed by non-random X-chromosome inactivation.

X-chromosome inactivation analysis was performed in order to assess the clonal origin of non-medullary thyroid tumours and to distinguish between multicentricity and multifocality in multiple papillary thyroid carcinoma (PTC). One hundred and thirteen tumour samples from 31 patients with isolated PTC, 16 patients with multinodular PTC, 14 patients with follicular thyroid adenoma (FTA) and 15 patients with follicular thyroid carcinoma (FTC) were collected. The corresponding normal thyroid tissues were analysed, and in 14 cases, tumour-surrounding tissue was also studied. Genomic DNA was digested with HpaII and HhaI previous to PCR amplification of the polymorphic CAG repeat, on exon 1 of the human androgen receptor gene (HUMARA). PCR products were analysed by denaturing gel electrophoresis, silver staining and densitometric analysis. PCR products were also used to determine the number of CAG repeats of patients with isolated PTC, FTA, FTC and of 41 healthy volunteers. Heterozygosity for the HUMARA polymorphism was found in 64/76 (84%) cases. Lyonization of the thyroid was observed in 15/76 (20%) cases, which were excluded from clonal analysis. Except for two cases of isolated PTC, all tumour samples studied presented monoclonal X-inactivation patterns, while normal thyroid tissue was polyclonal. Monoclonal patterns were also found in 4/14 tumour-surrounding tissues. No difference was found in the length of CAG alleles between patients and controls. Of eight informative cases of multinodular PTC, three showed evidence of multicentricity and five revealed patterns consistent with multifocality. Both isolated and multinodular PTC as well as FTA and FTC are of monoclonal origin. Our results also suggest that approximately one-third of multiple PTC have an independent origin for the different nodules (multicentricity). Monoclonality was also found in tissues surrounding some PTC nodules. No association was found between the length of CAG alleles and thyroid malignancies.

Immunostaining for ret oncogene proteins in papillary thyroid carcinoma: a correlation of ret immunoreactivity and potential of lymph node metastasis.

Ret oncogenes, particularly Ret/PTC, have been associated with the potential of local invasion of papillary thyroid carcinoma (PTC). The purpose of this study was to investigate the correlation between the Ret oncogene expression and the potential of lymph node metastasis of PTC. A total of 107 PTC were microscopically reviewed to identify areas of infiltrating carcinoma (IC). IC was defined as tumor cells disposed in a haphazard pattern and in lobules, nests, follicles, or single cells within a desmoplastic or sclerotic stroma. All cases were submitted to immunostaining for Ret oncogene. There were 36 noninfiltrating PTC with lymph node metastasis in 1 case and 71 infiltrating PTC with lymph node metastasis in 40 cases. For non-PTC, the positive immunoreactivity was often weak to moderate and focal. For infiltrating PTC with IC, the IC displayed strong immunoreactivity. The noninfiltrating component of PTC with IC usually showed stronger reactivity than PTC without an infiltrating component. Furthermore, 36 of 40 metastatic PTC in lymph node were immunoreactive. Three follicular adenomas with areas of scar caused by fine-needle aspiration biopsy were not immunoreactive for Ret. In view of the high potential of infiltrating PTC for lymph node metastasis, distinction of this type of carcinoma from its noninfiltrating form is clinically important. Because immunoreactivity for Ret is usually positive in areas of infiltrating PTC and is often negative or focally positive in noninfiltrating PTC, immunostaining for Ret is helpful to identify infiltrating PTC and distinguish it from changes caused by fine-needle aspiration biopsy in benign thyroid lesions.