Thyroid Fine-needle Aspiration Biopsy Specimens Research Articles

Whole-Transcriptome Profiling of Thyroid Nodules Identifies Expression-Based Signatures for Accurate Thyroid Cancer Diagnosis

Due to the limitations of fine-needle aspiration biopsy (FNAB) cytopathology, many individuals who present with thyroid nodules eventually undergo thyroid surgery to diagnose thyroid cancer. The objective of this study was to use whole-transcriptome profiling to develop and validate a genomic classifier that significantly improves the accuracy of preoperative thyroid cancer diagnosis. Nucleic acids were extracted and amplified for microarray expression analysis on the Affymetrix Human Exon 1.0 ST GeneChips from 1-mm-diameter formalin-fixed and paraffin-embedded thyroid tumor tissue cores. A training group of 60 thyroidectomy specimens (30 cancers and 30 benign lesions) were used to assess differential expression and for subsequent generation of a genomic classifier. The classifier was validated in a blinded fashion on a group of 31 formalin-fixed and paraffin-embedded thyroid FNAB specimens. Expression profiles of the 57 thyroidectomy training and 31 FNAB validation specimens that passed a series of quality control steps were analyzed. A genomic classifier composed of 249 markers that corresponded to 154 genes, had an overall validated accuracy of 90.0% in the 31 patient FNAB specimens and had positive and negative predictive values of 100% and 85.7%, respectively. The majority of the identified markers that made up the classifier represented non-protein-encoding RNAs. Whole-transcriptome profiling of thyroid nodule surgical specimens allowed for the development of a genomic classifier that improved the accuracy of preoperative thyroid cancer FNAB diagnosis.

Is There a Role for On-Site Evaluation of Thyroid Fine Needle Aspiration to Reduce the Nondiagnostic Rate?

The use of immediate on-site evaluation of fine-needle aspiration biopsy (FNAB) specimens can determine the adequacy of specimens and provides a specific preliminary diagnosis. In this prospective study, we evaluated the impact of on-site assessment of thyroid FNAB performed under ultrasound guidance. Totally, 204 (170 female, 34 male) patients (102 on site, 102 control group) were included. The patients were randomized on site and regular cytologic examination groups. Quick May-Grünwald Giemsa stain was used for on-site examination and FNA was continued until adequate aspirate for optimal cytological examination. Two (2.0 %) of the 102 patients evaluated with on-site examination had a nondiagnostic result. However, 16 (15.7 %) of the 102 patients examined by regular cytologic examination method, had nondiagnostic result. The difference between these two groups was statistically significant (p < 0.0001). The major cause of a nondiagnostic thyroid FNAB specimen is the failure to aspirate a sufficient number of cells necessary for diagnosis cystic lesions. Immediate on-site evaluation can significantly decrease the nondiagnostic rate of thyroid FNAB specimens.

Reduction of False-Negative Papillary Thyroid Carcinomas by the Routine Analysis of BRAFT1799A Mutation on Fine-Needle Aspiration Biopsy Specimens

To evaluate prospectively the usefulness of the routine determination of BRAF(T1799A) mutation on thyroid fine-needle aspiration biopsy (FNAB) to detect cytopathology false negative papillary thyroid carcinomas (PTC) and, therefore, as a tool to improve the sensitivity of the preoperative cytopathological diagnosis of PTC in thyroid nodules. FNAB is the most reliable diagnostic test to discriminate between malignant and benign thyroid nodules, but nondiagnostic results remain a clinical management dilemma. BRAF(T1799A) mutation is the most prevalent genetic alteration in thyroid cancers and is specific for PTC, characteristics that make it the most potentially helpful genetic tool to improve the diagnostic accuracy of FNAB. An exhaustive recruitment of all patients subjected to thyroid FNAB in our institution during 4 years was performed. BRAF(T1799A) mutation was determined on thyroid FNAB specimens by PCR and restriction fragment length polymorphism, plus direct sequencing in positive samples. BRAF(T1799A) mutation on FNAB detected 47.2% (17/36) of PTC cases. It confirmed preoperatively 45.5% (5/11) of the PTC cases in the indeterminate category and decreased the rate of cytopathology false-negatives in 33.3% (6/18), improving the combined (BRAF(T1799A) mutation + cytopathological analysis) sensitivity of the detection of PTC on FNAB in 16.7%. BRAF(T1799A) mutation improves the diagnosis of PTC on FNAB, mainly because of the detection of cytopathology false-negatives, and it can be helpful in the routine analysis of thyroid nodules, especially in clinical settings with moderate sensitivity to detect PTC on FNAB.

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

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. 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. 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. 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.

Analysis of Correlation between the Process of Thyroid Fibrosis and TGFB1 Gene Expression Level in Fine-needle Aspiration Biopsy (FNAB) Thyroid Specimens Collected from Patients with Hashimoto's Thyroiditis and Non-toxic Goitre

Transforming growth factor beta 1 (TGFB1) stimulates the production of various extracellular matrix components; at the same time, it inhibits matrix degradation. These actions of TGFB1 contribute to tissue repair, however, an altered expression of TGFB1 can be a causative factor of fibrosis processes, including thyroid fibrosis which follows chronic thyroiditis. The aim of our study was to examine a potential correlation between TGFB1 gene expression level in fine-needle aspiration biopsy (FNAB) thyroid specimens and fibrosis of the thyroid gland in two types of thyroid lesions. Fibrosis of the thyroid tissue was assessed, based on the expression levels of fibrosis-associated genes (COL1A1 and COL3A1) in thyroid FNAB samples, on the FNAB specimen cellularity and other features of the tissue fibrosis assessed during cytological examination, as well as on the size of thyroid gland and its function. Following routine cytological examination, 63 thyroid FNAB specimens, received from patients with Hashimoto's thyroiditis (HT, n=30) and non-toxic goitre (NTG, n=33), were quantitatively evaluated regarding TGFB1, COL1A1 and COL3A1 expression level by real-time PCR in the ABI PRISM 7500 Sequence Detection System. The obtained results showed statistically significant differences regarding the expression level (RQ) of TGFB1 and of COL1A1 genes between the groups with HT and with NTG (higher expression in HT group). No significant differences, concerning the expression level of COL3A1 gene, were observed for the studied groups (HT vs. NTG). In HT group statistically significant correlation was found between TGFB1 gene and COL3A1 gene expression levels (p<0.05). The correlation in question might suggest excessive extracellular matrix deposition and could--possibly--contribute to thyroid fibrosis mechanism in the course of chronic thyroiditis.

Relative quantification of PIK3CA gene expression level in fine-needle aspiration biopsy thyroid specimens collected from patients with papillary thyroid carcinoma and non-toxic goitre by real-time RT-PCR

BackgroundRecent studies have shown that the phosphatidylinositol 3-kinase (PI3K) signaling pathway is important regulator of many cellular events, including apoptosis, proliferation and motility. PI3K pathway alterations (PIK3CA gene mutations and/or amplification) have been observed in various human tumours. In the majority of diagnosed cases, mutations are localized in one of the three "hot spots" in the gene, responsible for coding catalytic subunit α of class I PI3K (PIK3CA). Mutations and amplification of PIK3CA gene are characteristic for thyroid cancer, as well.MethodsThe aim of our study was to examine a gene expression level of PIK3CA in fine-needle aspiration biopsy (FNAB) thyroid specimens in two types of thyroid lesions, papillary thyroid carcinoma (PTC) and non-toxic goitre (NTG). Following conventional cytological examination, 42 thyroid FNAB specimens, received from patients with PTC (n = 20) and NTG (n = 22), were quantitatively evaluated regarding PIK3CA expression level by real-time PCR in the ABI PRISM® 7500 Sequence Detection System.ResultsSignificantly higher expression level (RQ) of PIK3CA in PTC group has been noted in comparison with NTG group (p < 0.05).ConclusionThese observations may suggest role of PIK3CA alterations in PTC carcinogenesis.

Is BRAF Mutation Screening Useful for Preoperative Risk Stratification in Papillary Thyroid Cancer?

Evaluation of: Xing M, Clark D, Guan H et al.: BRAF mutation testing of thyroid fine-needle aspiration biopsy specimens for preoperative risk stratification in papillary thyroid cancer. J. Clin. Oncol. 27(18), 2977–2982 (2009). Although the majority of patients with papillary thyroid cancer are effectively treated with thyroidectomy and selective use of postoperative 131I therapy, disease persistence/recurrence can afflict a proportion of patients after the initial treatments. BRAF mutations, present in a large proportion of papillary thyroid cancers, illustrate one of the most impressive examples of phenotype–genotype correlation in human pathology. In this study, the authors propose that preoperative BRAF mutation testing of fine-needle aspiration biopsy specimens provides a novel tool for a preoperative risk stratification strategy for predicting the extent of initial disease and subsequent clinical outcomes.

BRAF Mutation Testing of Thyroid Fine-Needle Aspiration Biopsy Specimens for Preoperative Risk Stratification in Papillary Thyroid Cancer

This study investigated the utility of BRAF mutation testing of thyroid fine-needle aspiration biopsy (FNAB) specimens for preoperative risk stratification in papillary thyroid cancer (PTC). We assessed the T1799A BRAF mutation status in thyroid FNAB specimens obtained from 190 patients before thyroidectomy for PTC and its association with clinicopathologic characteristics of the tumor revealed postoperatively. We observed a significant association of BRAF mutation in preoperative FNAB specimens with poorer clinicopathologic outcomes of PTC. In comparison with the wild-type allele, BRAF mutation strongly predicted extrathyroidal extension (23% v 11%; P = .039), thyroid capsular invasion (29% v 16%; P = .045), and lymph node metastasis (38% v 18%; P = .002). During a median follow-up of 3 years (range, 0.6 to 10 years), PTC persistence/recurrence was seen in 36% of BRAF mutation-positive patients versus 12% of BRAF mutation-negative patients, with an odds ratio of 4.16 (95% CI, 1.70 to 10.17; P = .002). The positive and negative predictive values for preoperative FNAB-detected BRAF mutation to predict PTC persistence/recurrence were 36% and 88% for overall PTC and 34% and 92% for conventional PTC, respectively. Preoperative BRAF mutation testing of FNAB specimens provides a novel tool to preoperatively identify PTC patients at higher risk for extensive disease (extrathyroidal extension and lymph node metastases) and those who are more likely to manifest disease persistence/recurrence. BRAF mutation, as a powerful risk prognostic marker, may therefore be useful in appropriately tailoring the initial surgical extent for patients with PTC.

The Impact of Assessing Specimen Adequacy and Number of Needle Passes for Fine-Needle Aspiration Biopsy of Thyroid Nodules

Fine-needle aspiration biopsy (FNAB) of thyroid nodules is a safe, cost-effective procedure but the rates of inadequate cytology specimens range from approximately 1% to 15%. This study tests the hypothesis that ultrasonographically (US) guided FNAB and onsite assessment of cytology improves the adequacy rate of FNAB. A retrospective analysis was performed on 693 thyroid FNAB specimens obtained with and without ultrasound guidance and with or without onsite cytology assessment. Overall, 29 specimens (4%) were inadequate for diagnosis. Among 163 cystic nodules and 530 solid nodules, inadequacy rates were 15% (n = 24) and 1% (n = 5) respectively (p = 0.0001). An onsite assessment of cytology for adequacy was done in 550 cases (83%), which was more accurately performed by a cytopathologist (97%) than a cytotechnologist (93%, p = 0.015). With US-guided FNAB, 3% of the cytology specimens were inadequate, compared to a 7% rate when US was not done (p = 0.003). The mean number of needle punctures necessary for an adequate specimen was 3.8 +/- 0.06 (median, 3.0; range, 1-11), which was different among various types of doctors, ranging from 3.2 +/- 0.07 to 5.4 +/- 0.12 (p = 0.001 analysis of variance [ANOVA]). The fewest number of needle passes to achieve an adequate specimen were required by university endocrinologists and pathologists working together (average, 3.2 +/- 0.07; median, 3.0; range, 1-11). Sample inadequacy rate varied significantly among physician groups, ranging from 3% to 18% (p = 0.0001 ANOVA). Stepwise regression analysis showed that onsite assessment of cytology, US-guided FNAB (p = 0.16), and cystic nature of the nodule (p < 0.0001 for all) correlated with adequacy of the specimen. We conclude that US-guided FNAB with onsite evaluation of cytology specimens substantially increases the adequacy of cytology specimens and decreases the number of required needle passes, which ultimately reduces patient discomfort and diagnostic errors, thus raising the question as to whether this should eventually become the standard of care. We believe this is a goal that training programs should strive to achieve.

Fine-needle aspiration biopsy diagnosis of follicular variant of papillary thyroid cancer: Therapeutic implications

Objective: Frozen-section analysis of follicular lesions is often inconclusive because capsular or vascular invasions are the hallmarks of malignancy with this technique and may not be seen in the particular field studied. Using preoperative fine-needle aspiration biopsy specimens, we attempted to identify malignant follicular lesions and compare these results against frozen-section analysis. Methods: A retrospective study of 1000 consecutive thyroid fine-needle aspiration biopsy specimens was performed. Surgical pathologic correlation was available in 179 cases. Results: Fine-needle aspiration biopsy yielded a suspicious or positive rate of 23%. Surgical pathology was available in 179 patients, of which 95% had thyroid cancer. The follicular variant of papillary cancer was identified in 26 cases, or 15% of the positive cases. Frozen-section analysis yielded false-negative results in 7 of these 26 cases (27%). Conclusions: Preoperative recognition of the follicular variant of papillary cancer by fine-needle aspiration biopsy may reduce the overall incidence of false-negative frozen-section findings. (Otolaryngol Head Neck Surgery 1998;119:600-2.)

Selective expression of CD44 cell-adhesion molecule in thyroid papillary carcinoma fine-needle aspirates.

Recent descriptions of numerous pitfalls in the cytologic diagnosis of thyroid papillary carcinoma on fine-needle aspiration biopsy specimens have prompted studies of new ancillary diagnostic methods. We evaluated the potential use of immunocytochemical staining of thyroid fine-needle aspiration biopsy specimens for CD44, a glycosylated cartilage link protein associated with extracellular matrix adhesion and lymphocyte homing. Fourteen of 16 (88%) classic, surgically confirmed, thyroid aspiration biopsies stained intensely positive for this marker, whereas 0 of 30 (0%) similarly-processed benign aspirates from colloid nodules showed immunoreactivity for CD44 antigen. From this study, we conclude that most papillary carcinomas of the thyroid express the celladhesion molecule CD44, which may be of clinical value in confirming the diagnosis on borderline fine-needle aspiration specimens. Further study of CD44 expression may prove of significant interest in explaining the unusual mode of spread and clinical course of this disease.