Interinstitutional review of thyroid fine-needle aspirations: impact on clinical management of thyroid nodules

Fine-needle aspiration of cutaneous, subcutaneous, and intracavitary masses in dogs and cats using 22- vs 25-gauge needles

BACKGROUND

Fine-needle aspiration (FNA) is a common procedure as a diagnostic tool in veterinary medicine. However, it is unclear whether the gauge of the needle affects the quality of cytology.

OBJECTIVE

This study compared the quality of cytologic samples obtained via FNA using 22- or 25-gauge needles.

METHODS

Fine-needle aspiration was performed on 50 masses (cutaneous, subcutaneous, or intracavitary) obtained from client-owned animals. The size of the needle was randomly assigned using either of the following two sequences: 22-25-22 gauge or 25-22-25 gauge. Samples were evaluated by two board-certified clinical pathologists to assess cellularity, blood contamination, amount of cellular debris, degree of cellular trauma, and the overall ability to make a diagnosis for each sample.

RESULTS

No significant difference was detected between the 22- and 25-gauge needle samples for cellularity, whereas a significant difference was present for blood contamination, amount of cellular debris, and degree of cellular trauma. The overall ability to make a diagnosis was not significantly affected by the needle gauge. The degree of cellular trauma was significantly increased in intracavitary samples.

CONCLUSIONS AND CLINICAL RELEVANCE

Needle gauge is a contributing factor to FNA sample quality. However, it did not affect the overall ability to make a diagnosis. Samples obtained using 25-gauge needles resulted in less blood contamination yet increased cellular trauma compared to 22-gauge needle samples.

The Use of the Bethesda System for Reporting Thyroid Cytopathology in Korea: A Nationwide Multicenter Survey by the Korean Society of Endocrine Pathologists

Background

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has standardized the reporting of thyroid cytology specimens. The objective of the current study was to evaluate the nationwide usage of TBSRTC and assess the malignancy rates in each category of TBSRTC in Korea.

Methods

Questionnaire surveys were used for data collection on the fine needle aspiration (FNA) of thyroid nodules at 74 institutes in 2012. The incidences and follow-up malignancy rates of each category diagnosed from January to December, 2011, in each institute were also collected and analyzed.

Results

Sixty out of 74 institutes answering the surveys reported the results of thyroid FNA in accordance with TBSRTC. The average malignancy rates for resected cases in 15 institutes were as follows: nondiagnostic, 45.6%; benign, 16.5%; atypical of undetermined significance, 68.8%; suspicious for follicular neoplasm (SFN), 30.2%; suspicious for malignancy, 97.5%; malignancy, 99.7%.

Conclusions

More than 80% of Korean institutes were using TBSRTC as of 2012. All malignancy rates other than the SFN and malignancy categories were higher than those reported by other countries. Therefore, the guidelines for treating patients with thyroid nodules in Korea should be revisited based on the malignancy rates reported in this study.

Sinonasal malignancy: What to do with an unexpected pathology result?

BACKGROUND

Endoscopic sinus surgery has become the mainstay in surgical treatment of sinusitis and nasal polyps. While rare, diagnostic discrepancies or pathological contamination during routine specimen analysis has been described. Thus, an accurate diagnosis and indication for surgery are mandatory before proceeding with surgical intervention.

METHODS

We present the case of a 40-year-old female patient who underwent endoscopic sinus surgery (ESS) for chronic sinusitis without nasal polyposis and fragments of squamous cell carcinoma (SCC) were found in the pathology specimen.

RESULTS

We propose an algorithm to help guide physicians presented with a tissue diagnosis that does not match the clinical scenario. Moreover, we discuss strategies to help prevent medical errors and the importance of DNA genetic analysis in this situation.

CONCLUSION

When an unexpected diagnosis occurs, the pathology slides should be reviewed for a second opinion. If the unexpected diagnosis is confirmed, the tissue should undergo STR genetic analysis to ensure against tissue contamination.

Interpretive Diagnostic Error Reduction in Surgical Pathology and Cytology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the Association of Directors of Anatomic and Surgical Pathology

CONTEXT

Additional reviews of diagnostic surgical and cytology cases have been shown to detect diagnostic discrepancies.

OBJECTIVE

To develop, through a systematic review of the literature, recommendations for the review of pathology cases to detect or prevent interpretive diagnostic errors.

DESIGN

The College of American Pathologists Pathology and Laboratory Quality Center in association with the Association of Directors of Anatomic and Surgical Pathology convened an expert panel to develop an evidence-based guideline to help define the role of case reviews in surgical pathology and cytology. A literature search was conducted to gather data on the review of cases in surgical pathology and cytology.

RESULTS

The panel drafted 5 recommendations, with strong agreement from open comment period participants ranging from 87% to 93%. The recommendations are: (1) anatomic pathologists should develop procedures for the review of selected pathology cases to detect disagreements and potential interpretive errors; (2) anatomic pathologists should perform case reviews in a timely manner to avoid having a negative impact on patient care; (3) anatomic pathologists should have documented case review procedures that are relevant to their practice setting; (4) anatomic pathologists should continuously monitor and document the results of case reviews; and (5) if pathology case reviews show poor agreement within a defined case type, anatomic pathologists should take steps to improve agreement.

CONCLUSIONS

Evidence exists that case reviews detect errors; therefore, the expert panel recommends that anatomic pathologists develop procedures for the review of pathology cases to detect disagreements and potential interpretive errors, in order to improve the quality of patient care.

Improved cytodiagnostics and quality of patient care through double reading of selected cases by an expert cytopathologist

Double reading may be a valuable tool for improving the quality of patient care by restoring diagnostic errors before final sign-out, but standard double reading would significantly increase costs of pathology. The aim of this study was to assess the added value of routine double reading of defined categories of clinical cytology specimens by specialized cytopathologists. Specialized cytopathologists routinely re-diagnosed blinded defined categories of clinical cytology specimens that had been signed out by routine pathologists from January 2012 up to December 2013. Major and minor discordance rates between initial and expert diagnoses were determined, and both diagnoses were validated by comparison with same-site histological follow-up. Initial and expert diagnoses were concordant in 131/218 specimens (60.1 %). Major and minor discordances were present in 28 (12.8 %) and 59 (27.1 %) specimens, respectively. Pleural fluid, thyroid and urine specimens showed the highest major discordance rates (19.4, 19.2 and 16.7 %, respectively). Histological follow-up (where possible) supported the expert diagnosis in 95.5 % of specimens. Our implemented double reading strategy of defined categories of cytology specimens showed major discordance in 12.8 % of specimens. The expert diagnosis was supported in 95.5 % of discordant cases where histological follow-up was available. This indicates that this double reading strategy is worthwhile and contributes to better cytodiagnostics and quality of patient care, especially for suspicious pleural fluid, thyroid and urine specimens. Our results emphasize that cytopathology is a subspecialization of pathology and requires specialized cytopathologists.

The Bethesda System for Reporting Thyroid Fine-Needle Aspiration Cytology: A Kuwaiti Experience - A Cytohistopathological Study of 374 Cases

INTRODUCTION

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) identifies 6 diagnostic categories in which the risk of malignancy increases respectively. The aim of our study was to assess TBSRTC reporting in our hospital and to evaluate its specificity based on cytohistological correlation.

METHODS

A histological diagnosis was available in 374 (110 males and 264 females) out of 7,809 thyroid aspirates examined at Mubarak Al-Kabeer Hospital, Kuwait, from 2004 to 2012. The aspirates were classified in accordance with TBSRTC.

RESULTS

Thyroid aspirates were classified as nondiagnostic (n = 18; 4.8%), benign (n = 114; 30.5%); atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS; n = 59; 15.8%), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN; n = 17; 4.5%), suspicious for malignancy (SM; n = 80; 21.4%), or malignant (n = 86; 23.0%). In 75 of 86 malignant cases, a papillary carcinoma was detected. There were 3 (1.6%) false-positive aspirates and the sensitivity, specificity, negative predictive value, and positive predictive value were 91.0, 61.9, 84.2, and 75.3%, respectively.

CONCLUSIONS

Our results are fairly comparable to those of various previous studies in the SM, AUS/FLUS, and SFN categories. The higher rates observed in the nondiagnostic and benign categories were possibly due to limited guided aspirations and a lack of on-site evaluation for all cases.

Evaluation of indeterminate thyroid cytology by second-opinion diagnosis or repeat fine-needle aspiration: which is the best approach?

OBJECTIVE

This study investigated a published series evaluating the role of second-opinion diagnosis (SOD) or repeat fine-needle aspiration cytology (RFNA) for indeterminate thyroid aspirates.

STUDY DESIGN

Twenty-three studies were selected and the following parameters were analyzed: disagreement between SOD or RFNA and the original diagnosis (OD), reclassification of OD according to the Bethesda system for reporting thyroid cytopathology, the rate of definitive diagnosis and the diagnostic performance of SOD and RFNA.

RESULTS

7,154 thyroid FNAs were retrieved from 9 studies that investigated the role of SOD, including 1,048 (14.6%) cases originally reported as indeterminate. The 14 studies that analyzed the role of thyroid RFNA comprised 67,581 FNAs and included 7,246 (10.7%) indeterminate cases. A definitive diagnosis was achieved by SOD in 450 cases (42.9%) and RFNA in 1,645 cases (57.2%, p=0.0001). Based on cases with histological follow-up, SOD demonstrated significantly higher rates of positive predictive value and accuracy than RFNA (55.8 vs. 37.7%, p=0.0001; 67.4 vs. 56.0%, p=0.0034, respectively).

CONCLUSIONS

Both SOD and RFNA demonstrated an improvement in the diagnosis of initially indeterminate thyroid FNAs. RFNA achieved a definitive diagnosis for the majority of indeterminate cases. Regarding histological follow-up, SOD was shown to be more accurate than RFNA.

Malignancy rate of thyroid nodules defined as follicular lesion of undetermined significance and atypia of undetermined significance in thyroid cytopathology and its relation with ultrasonographic features

Fine-needle aspiration biopsy (FNAB) has been widely accepted as the most accurate, safe, and cost-effective method for evaluation of thyroid nodules. The most challenging category in FNAB is atypia of undetermined significance (AUS) and follicular lesion of undetermined significance (FLUS). The Bethesda system (BS) recommends repeat FNAB in that category due to its low risk of malignancy. In our study, we aimed to investigate the malignancy rate of thyroid nodules of AUS and FLUS and whether there were different malignancy rates among the different patterns in this category, and to evaluate the presence of biochemical, clinical, and echographic features possibly predictive of malignancy related to AUS and FLUS. Data of 268 patients operated for AUS and FLUS cytology were screened retrospectively. Ultrasonographic features and thyroid function tests, thyroid antibodies, scintigraphy, and histopathological results were evaluated. Of the 268 patients' results, 276 nodules are evaluated. Malignancy rates were 24.3 % in the AUS group, 19.8 % in the FLUS group, and 22.8 % in both groups. In the evaluation of all nodules, the predictive features of malignancy are hypoechogenicity and peripheral vascularization of the nodule. We determined that the malignancy rates in these nodules are higher than that in the literature rate. This high ratio may be due to the fact that we studied only patients who underwent surgery. The ultrasonographic features alone may be insufficient to predict the malignancy; therefore, all the clinical and ultrasonographic features must be considered in the evaluation of the thyroid nodules. In addition, we think that the recommended management of repeat FNAB in these groups must be reconsidered with the clinical and ultrasonographic features.

Incidence and malignancy rates of diagnoses in the bethesda system for reporting thyroid aspiration cytology: an institutional experience

BACKGROUND

The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) uses six diagnostic categories to standardize communication of thyroid fine-needle aspiration (FNA) interpretations between clinicians and cytopathologists. Since several studies have questioned the diagnostic accuracy of this system, we examined its accuracy in our hospital.

METHODS

We calculated the incidences and malignancy rates of each diagnostic category in the BSRTC for 1,730 FNAs that were interpreted by four cytopathologists in Gangnam Severance Hospital between October 1, 2011, and December 31, 2011.

RESULTS

The diagnostic incidences of categories I-VI were as follows: 13.3%, 40.6%, 9.1%, 0.4%, 19.3%, and 17.3%, respectively. Similarly, the malignancy rates of these categories were as follows: 35.3%, 5.6%, 69.0%, 50.0%, 98.7%, and 98.9%, respectively. In categories II, V, and VI, there were no statistically significant differences in the ranges of the malignancy rates among the four cytopathologists. However, there were significant differences in the ranges for categories I and III.

CONCLUSIONS

Our findings suggest that institutions that use the BSRTC should regularly update their diagnostic criteria. We also propose that institutions issue an annual report of incidences and malignancy rates to help other clinicians improve the case management of patients with thyroid nodules.

Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study

IMPORTANCE

There is wide variation in the management of thyroid nodules identified on ultrasound imaging.

OBJECTIVE

To quantify the risk of thyroid cancer associated with thyroid nodules based on ultrasound imaging characteristics.

METHODS

Retrospective case-control study of patients who underwent thyroid ultrasound imaging from January 1, 2000, through March 30, 2005. Thyroid cancers were identified through linkage with the California Cancer Registry.

RESULTS

A total of 8806 patients underwent 11,618 thyroid ultrasound examinations during the study period, including 105 subsequently diagnosed as having thyroid cancer. Thyroid nodules were common in patients diagnosed as having cancer (96.9%) and patients not diagnosed as having thyroid cancer (56.4%). Three ultrasound nodule characteristics--microcalcifications (odds ratio [OR], 8.1; 95% CI, 3.8-17.3), size greater than 2 cm (OR, 3.6; 95% CI, 1.7-7.6), and an entirely solid composition (OR, 4.0; 95% CI, 1.7-9.2)--were the only findings associated with the risk of thyroid cancer. If 1 characteristic is used as an indication for biopsy, most cases of thyroid cancer would be detected (sensitivity, 0.88; 95% CI, 0.80-0.94), with a high false-positive rate (0.44; 95% CI, 0.43-0.45) and a low positive likelihood ratio (2.0; 95% CI, 1.8-2.2), and 56 biopsies will be performed per cancer diagnosed. If 2 characteristics were required for biopsy, the sensitivity and false-positive rates would be lower (sensitivity, 0.52; 95% CI, 0.42-0.62; false-positive rate, 0.07; 95% CI, 0.07-0.08), the positive likelihood ratio would be higher (7.1; 95% CI, 6.2-8.2), and only 16 biopsies will be performed per cancer diagnosed. Compared with performing biopsy of all thyroid nodules larger than 5 mm, adoption of this more stringent rule requiring 2 abnormal nodule characteristics to prompt biopsy would reduce unnecessary biopsies by 90% while maintaining a low risk of cancer (5 per 1000 patients for whom biopsy is deferred).

CONCLUSIONS AND RELEVANCE

Thyroid ultrasound imaging could be used to identify patients who have a low risk of cancer for whom biopsy could be deferred. On the basis of these results, these findings should be validated in a large prospective cohort.

A tertiary center's experience with second review of 3885 thyroid cytopathology specimens

BACKGROUND

Although the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) has standardized the diagnostic terminology for thyroid fine-needle aspiration (FNA), morphological interpretation remains subjective, and interobserver discrepancies are expected. This study quantifies the frequency and magnitude of these discrepancies in a single tertiary center's experience and elucidates key factors that are associated with changes in diagnosis.

METHODS

Institutional consultation for 3885 thyroid cytological samples over 45 months were reviewed. BSRTC classification made by the sending institution was compared with that of our institution. An ANOVA was performed to determine factors that may be associated with interinstitutional diagnostic differences. Histopathology diagnoses were available for 1049 (27%) nodules; the malignancy rates for inside and outside BSRTC classifications were calculated.

RESULTS

There were 937 1-step changes and 301 ≥2-step diagnostic discrepancies comprising 24% and 8% of all cases, respectively. Second review decreased the indeterminate rate 38% to 28% (P < .000001). Indeterminate diagnostic category before second review, low specimen cellularity, Hashimoto's thyroiditis, and low volume of consults from the sending institution were associated with discordance. Of the 1049 thyroid nodules operated for which unequivocal histopathology was available, the malignancy rates for the BSRTC categories before and after second review were compared. Categorical upgrades were associated with a malignancy rate of 84%, whereas downgrades were associated with a malignancy rate of 38% (P < .000001).

CONCLUSION

This is the largest series to date of thyroid cytology second review. The BSRTC classification changed 32% of the time, potentially resulting in significant changes in clinical and surgical management. Because certain specimen characteristics (indeterminate diagnostic category before second review, low specimen cellularity, Hashimoto's thyroiditis, and low volume of consults from the sending institution) were particularly associated with a diagnosis change, morphological second review may be of potential benefit in these settings.

A general method to derive robust organ-specific gene expression-based differentiation indices: application to thyroid cancer diagnostic

Differentiation is central to development, while dedifferentiation is central to cancer progression. Hence, a quantitative assessment of differentiation would be most useful. We propose an unbiased method to derive organ-specific differentiation indices from gene expression data and demonstrate its usefulness in thyroid cancer diagnosis. We derived a list of thyroid-specific genes by selecting automatically those genes that are expressed at higher level in the thyroid than in any other organ in a normal tissue's genome-wide gene expression compendium. The thyroid index of a tissue was defined as the median expression of these thyroid-specific genes in that tissue. As expected, the thyroid index was inversely correlated with meta-PCNA, a proliferation metagene, across a wide range of thyroid tumors. By contrast, the two indices were positively correlated in a time course of thyroid-stimulating hormone (TSH) activation of primary thyrocytes. Thus, the thyroid index captures biological information not integrated by proliferation rates. The differential diagnostic of follicular thyroid adenomas and follicular thyroid carcinoma is a notorious challenge for pathologists. The thyroid index discriminated them as accurately as did machine-learning classifiers trained on the genome-wide cancer data. Hence, although it was established exclusively from normal tissue data, the thyroid index integrates the relevant diagnostic information contained in tumoral transcriptomes. Similar results were obtained for the classification of the follicular vs classical variants of papillary thyroid cancers, that is, tumors dedifferentiating along a different route. The automated procedures demonstrated in the thyroid are applicable to other organs.

The use of the Bethesda terminology in thyroid fine-needle aspiration results in a lower rate of surgery for nonmalignant nodules: a report from a reference center in Turkey

The Bethesda system (BS) for reporting thyroid fine-needle aspiration (FNA), which classifies nodules as nondiagnostic (ND), benign (B), atypia/follicular lesion of undetermined significance (AUS/FLUS), suspicious for follicular neoplasm (SFN/FN), suspicious for malignancy (SFM), or malignant (M), uses clinically valuable management guidelines. The authors employed a similar in-house classification system (IS) for thyroid FNAs, using the categories of ND, B, suspicious follicular cells (SFC), follicular lesion/neoplasm (FL/FN), SFM, and M. The authors compared IS and BS, and assessed the utility of BS in clinical practice. A total of 581 nodules with cytological/histological follow-up were examined and indeterminate lesions by BS were reclassified. The sensitivity and specificity for malignancy using IS were similar to that of BS (77% vs 99%). However, when SFN/FN and SFM were both considered positive, the results for IS and BS were as follows: sensitivity, 85% versus 85%; specificity, 87% versus 94%; and diagnostic accuracy, 86% versus 90%, respectively. Discrepancies between cytological and histological data were evident in 35 cases among all categories of BS except AUS/FLUS. The rate of surgery for nonmalignant nodules was lesser (20% vs 9%) by BS. Among 34 AUS/FLUS cases with follow-up data, hypocellularity was the case in 11 (46%) nonneoplastic and 10 (100%) neoplastic nodules. The use of BS results in a lower rate of surgery for nonmalignant nodules even though patients with borderline cytopathologic features are still encountered. AUS/FLUS category can be separated into subgroups according to the factors causing difficulties in the interpretation. There is a need of accumulation of AUS/FLUS cases to do further evaluations and studies.

Significance of repeatedly nondiagnostic thyroid fine-needle aspirations

Nondiagnostic thyroid fine-needle aspirations are associated with a risk of malignancy that can be reduced with repeated aspiration. However, the significance of repeated nondiagnostic aspirates is less well studied. This study assessed the risk of malignancy for repeated nondiagnostic aspirates from a large series of cases using the results of histologic follow-up. From a series of 7,089 aspirates, there were 1,671 nondiagnostic aspirates (23.6%), and 235 of these (14.1%) had histologic follow-up. The risk of malignancy for a single nondiagnostic aspirate was 20.0% (47/235). A total of 51 cases had repeated aspiration. The risk of malignancy for cases with a second nondiagnostic aspirate was 0% (0/23), which was significantly less than for patients with a single nondiagnostic aspirate (20.0%; P = .03). Patients with 2 sequential nondiagnostic thyroid aspirates have a very low risk of malignancy. Cytologists should strive to better convey this risk in their reports.

Evidence-based evaluation of the risks of malignancy predicted by thyroid fine-needle aspiration biopsies

A National Cancer Institute (NCI) "Thyroid Fine-Needle Aspiration (FNA) State of the Science Conference" recently proposed standardized nomenclature and "risks of malignancies" associated with various diagnostic categories. We evaluated the evidence levels of the data used by NCI to predict malignancy risks and whether those estimates had clinical validity in our patient population.Eight hundred seventy-nine patients underwent thyroid FNA during 2006. FNA diagnoses were translated into NCI diagnostic categories, and 2-year follow-up retrospective information was obtained. Four percentages of malignancies were calculated for each diagnostic category using follow-up information from FNA, thyroidectomy, both, and all patients as denominators. 95% confidence intervals (CI) were estimated for all proportions, and results were analyzed with chi-square statistics. "Relative risk" calculations were performed using the percentage of malignancies in the entire population under study as a denominator.Most of the studies cited by the NCI provided incomplete and variable level III evidence based mainly on surgical follow-up. Among our patients, the percentages of malignancies calculated with follow-up data from all patients as the denominator were similar to the "risk estimates" proposed by the NCI, but estimates based on surgical follow-up overestimated the probability of thyroid malignancy for patients with FNA diagnosis of "benign" and "follicular lesions of undetermined significance" (FLUS). Relative risk and 95% CI calculations suggested that the NCI classification could be simplified into three categories: "benign," "FLUS + neoplasm," and "suspicious + malignant."

Interinstitutional consultation in fine-needle aspiration cytopathology: a study of 742 cases

BACKGROUND

The importance of interinstitutional consultation (IC) has been documented across a variety of surgical pathology organ systems. However, to the authors' knowledge, few studies exist regarding this practice within cytopathology and specifically within fine-needle aspiration cytology (FNAC).

METHODS

All FNAC cases between September 2002 and January 2007 were reviewed. Original diagnoses and second opinion diagnoses (SODs) were categorized as either no diagnostic disagreement, or minor diagnostic disagreement, or major diagnostic disagreement, and the latter was defined as either a 2-step deviation on a scale of "unsatisfactory, benign, atypical, suspicious, and malignant" or a change in treatment and/or prognosis. Outcome was determined by a review of the electronic medical record.

RESULTS

Among 742 FNAC cases from outside laboratories, there were minor disagreements in 132 cases (17.8%) and major disagreements in 69 cases (9.3%) compared with the SODs from the authors' laboratory. Follow-up was available for 60 of 69 major discrepancies. The SOD was supported on follow-up in 65% of major discrepancies, and the initial diagnosis was supported better in 33% of major discrepancies. In 55% of cases in which the original institution diagnosis was supported better, either no case slides were received for examination or the slides contained material that was considered nondiagnostic by the authors. An SOD prompted a change in clinical management in 32 of 742 patients (4.3%). Aspirates that were most prone to change in management or therapy were from the thyroid (13 cases), neck (soft tissue and lymph nodes; 9 cases), salivary gland (2 cases), and liver (2 cases). Of 60 major diagnostic disagreements, board-certified cytopathologists rendered an SOD in 44 cases, and 75% of the diagnoses were supported better by follow-up, whereas pathologists who were not board certified in cytopathology had only 38% of SODs supported.

CONCLUSIONS

Of 742 FNAC cases, 9.3% had major diagnostic disagreements; and, in 4.3%, patient management and therapy were altered. These results were similar to studies in surgical pathology emphasizing the importance of IC in FNAC. The authors concluded that FNAC IC benefits patient care.

Diagnostic terminology and morphologic criteria for cytologic diagnosis of thyroid lesions: a synopsis of the National Cancer Institute Thyroid Fine-Needle Aspiration State of the Science Conference

The National Cancer Institute (NCI) sponsored the NCI Thyroid Fine-needle Aspiration (FNA) State of the Science Conference on October 22-23, 2007 in Bethesda, MD. The two-day meeting was accompanied by a permanent informational website and several on-line discussion periods between May 1 and December 15, 2007 (http://thyroidfna.cancer.gov). This document summarizes matters regarding diagnostic terminology/classification scheme for thyroid FNA interpretation and cytomorphologic criteria for the diagnosis of various benign and malignant thyroid lesions. (http://thyroidfna.cancer.gov/pages/info/agenda/).

Recent developments in the clinical application of thyroid cancer biomarkers

PURPOSE OF REVIEW

The aim of this article is to provide an update on the status of the clinical application of thyroid cancer biomarkers.

RECENT FINDINGS

Our understanding of the tumor cell biology of thyroid cancer of follicular cell origin has improved and modern genomic technological tools are providing new data that may have clinical ramifications. The common somatic genetic changes in thyroid cancer of follicular cell origin (RET/PTC, NTRK, RAS, BRAF, PAX8-PPARgamma) are generally mutually exclusive, with distinct genotype-histologic subtype of thyroid cancer and genotype-phenotype associations observed. Mutation analysis in thyroid nodule fine needle aspiration biopsy has been applied to improve the diagnostic accuracy of fine needle aspiration biopsy and cytologic examination. Gene expression profiling studies have identified numerous diagnostic biomarkers of thyroid cancer that are beginning to be applied in fine needle aspiration biopsy samples to improve diagnosis. The BRAF mutation has recently been shown to be associated with disease aggressiveness, and as an independent prognostic biomarker.

SUMMARY

There has been significant progress toward identifying biomarkers that could improve the accuracy of fine needle aspiration biopsy in the evaluation of patients with thyroid nodule and predicting disease aggressiveness. Future clinical trials evaluating the accuracy and cost-effectiveness of applying these biomarkers in the management of thyroid neoplasm should be considered.

Genome-wide gene expression profiling suggests distinct radiation susceptibilities in sporadic and post-Chernobyl papillary thyroid cancers

Papillary thyroid cancers (PTCs) incidence dramatically increased in the vicinity of Chernobyl. The cancer-initiating role of radiation elsewhere is debated. Therefore, we searched for a signature distinguishing radio-induced from sporadic cancers. Using microarrays, we compared the expression profiles of PTCs from the Chernobyl Tissue Bank (CTB, n=12) and from French patients with no history of exposure to ionising radiations (n=14). We also compared the transcriptional responses of human lymphocytes to the presumed aetiological agents initiating these tumours, γ-radiation and H₂O₂. On a global scale, the transcriptomes of CTB and French tumours are indistinguishable, and the transcriptional responses to γ-radiation and H₂O₂ are similar. On a finer scale, a 118 genes signature discriminated the γ-radiation and H₂O₂ responses. This signature could be used to classify the tumours as CTB or French with an error of 15–27%. Similar results were obtained with an independent signature of 13 genes involved in homologous recombination. Although sporadic and radio-induced PTCs represent the same disease, they are distinguishable with molecular signatures reflecting specific responses to γ-radiation and H₂O₂. These signatures in PTCs could reflect the susceptibility profiles of the patients, suggesting the feasibility of a radiation susceptibility test.

Does Routine Consultation of Thyroid Fine-Needle Aspiration Cytology Change Surgical Management?

BACKGROUND

Routine secondary cytologic review of thyroid gland fine-needle aspiration (FNA) specimens in patients referred from other institutions has been the recommended practice at some medical centers. We sought to determine the concordance rates between FNA interpretations at referring institutions and our center to determine if they alter surgical management.

STUDY DESIGN

All thyroid gland FNAs referred to our center for cytopathologic opinion from June 2000 to August 2004 were reviewed. Patients in whom FNA biopsies were performed for thyroid cancer recurrences or core biopsies and patients in whom only a cytopathologic opinion was requested without a clinical consultation were excluded from the study. FNA results were divided into benign, indeterminate, suspicious, malignant, and nondiagnostic categories. FNA interpretations at our medical center and the referring institutions were compared with final histology results in patients who underwent operations.

RESULTS

One hundred forty-seven patients had secondary review of their thyroid gland FNA specimens. The overall concordance was 82%, with the highest concordance rate in the malignant category (95%) and the lowest in the suspicious category (62%, p<0.001). The sensitivity (94% versus 92%), specificity (76% versus 56%), and positive (93% versus 87%) and negative (79% versus 69%) predictive values were all higher on secondary review. Twenty-seven patients were found to have discordant FNA interpretations. As a result of the discordant FNA result, four patients had their surgical management decisions changed. Another four patients had appropriate oncologic thyroid resection as a result of the secondary review.

CONCLUSIONS

Our results suggest that routine secondary cytopathologic review of FNA specimens from referring institutions changes surgical management in some patients with thyroid neoplasms. We recommend this practice be widely used at other centers, especially for suspicious results.

Inter- and intraobserver reproducibility of thyroid fine needle aspiration cytology: an analysis of discrepant cases

OBJECTIVE

To determine the inter- and intraobserver reproducibility and analyse the discrepant cases of fine needle aspiration cytology (FNAC) of the thyroid.

METHODS

Cases of thyroid FNAC with a corresponding histological diagnosis were reviewed regarding the original cytological diagnoses by two observers. The final cytological diagnoses (FCD) included both concordant and consensus diagnoses. The inter- and intraobserver reproducibility and efficacy of thyroid FNAC were calculated based on the FCD.

RESULTS

A total of 97 FNAC cases with corresponding histopathological specimens were analysed. Although inter- and intraobserver disagreement in the cytological diagnoses occurred in about one-quarter of the cases analysed (24.7% and 23.7%, respectively), a substantial level of diagnostic interobserver (kappa = 0.71) and intraobserver (kappa = 0.66) reproducibility was observed. The efficacy of the method was 94.4%. Disagreement in the diagnosis was detected in 24 cases (24.7%), most of them (41.7%) for follicular lesions. Discordant cytological diagnoses between the two observers were represented by six (16.2%) of the 37 cases with an FCD of colloid nodule, five (41.7%) of the 12 cases of cellular follicular lesion, all three cases of follicular neoplasm, in two (6.3%) of the 32 cases of PTC, one (16.7%) of six cases of follicular neoplasm with a predominance of Hürthle cells and in one case of poorly differentiated neoplasia. Similarly, major disagreement in intraobserver cytological diagnoses was observed for the diagnosis of follicular lesions: 18 (78.3%) of a total of 23 discordant cases.

CONCLUSION

As discrepancies in the cytopathological diagnosis can have repercussions in the management of patients, all cases with a cytological diagnosis of follicular lesions/neoplams should be reviewed in multidisciplinary meetings thus minimizing interobserver variability.

Is fine-needle aspiration (FNA) of multiple thyroid nodules justified?

BACKGROUND

The clinical management of patients with solitary thyroid nodule is well established; however, the evaluation of patients with multiple thyroid nodules is controversial. The aim of this study was to assess if there is a correlation between the risk of malignancy and number of thyroid nodules.

DESIGN

The study cohort included 2,884 patients (2,410 females and 474 males) with 3,274 thyroid nodules that underwent FNA under ultrasound guidance between November 1997 and April 2004. Multiple thyroid nodules were aspirated in 360 patients; 2 in 332 (291 females, 41 males), 3 nodules in 26 (23 females, 3 males), and 4 nodules in 2 patients (1 female, 1 male). Subsequent information regarding the histological diagnosis was obtained in the cases that underwent surgical excision.

RESULTS

The average age for patients with single or multiple nodules was the same (51 yr). The FNA specimens were diagnosed as benign (n = 1,663, 51%), neoplasm (n = 880, 27%), suspicious for neoplasm or papillary carcinoma (n = 234, 7%), malignant (n = 187, 6%), and non-diagnostic (n = 310, 9%). Surgical excision was performed in 1,135 patients: 993 patients with single nodules and 142 patients with multiple nodules. The surgical pathology diagnosis was benign in 656 nodules (52%) and malignant in 596 nodules (48%). In the malignant category 153 tumors were papillary microcarcinoma (<1 cm). Excluding these cases, the malignancy rate was 39% in patients with single nodules, 41% with two nodules, and 21% with three nodules.

CONCLUSIONS

The cancer risk is similar for patients with one or two nodules over 1 cm and decreases with three or more thyroid nodules.

Diagnostic and prognostic value of angiogenesis-modulating genes in malignant thyroid neoplasms

BACKGROUND

Angiogenesis is an essential biologic event in the pathogenesis of human malignancies. We postulated that expression analysis of genes that modulate angiogenesis would identify differentially expressed genes that would help to distinguish benign from malignant thyroid neoplasms and serve as markers of aggressive differentiated thyroid cancer.

METHODS

A complementary DNA (cDNA) array with 96 genes that modulate angiogenesis was used to identify differentially expressed genes (2-fold higher or lower) in malignant versus benign thyroid neoplasms. Real-time quantitative polymerase chain reaction was used to confirm cDNA array expression data in 123 patients (4 normal thyroid, 26 hyperplastic nodules, 27 follicular adenomas, 23 follicular cancers, 18 follicular variant of papillary cancers, 25 papillary cancers).

RESULTS

Twenty-two genes were upregulated in malignant thyroid neoplasms by cDNA array analysis, but only 13 genes had higher messenger RNA (mRNA) expression levels in malignant than in benign thyroid neoplasms by real-time quantitative polymerase chain reaction (P < or = .04). Of the 13 differentially expressed genes, the combined use of angiopoietin 2 (ANGPT2) and tissue inhibitor of metalloproteinase 1 (TIMP1) mRNA expression levels was best for distinguishing malignant from benign thyroid neoplasms, with a sensitivity of 90%, specificity of 85%, positive predictive value of 75%, and negative predictive value of 94%. Epidermal growth factor receptor and ephrin B2 mRNA expression was elevated in higher TNM stage neoplasms and in patients with high-risk AMES (Age, distant Metastasis, Extrathyroidal invasion, and tumor Size) differentiated thyroid cancers (P < or = .005).

CONCLUSIONS

Angiopoietin 2 and tissue inhibitor of metalloproteinase 1 are diagnostic markers of malignant thyroid nodules and could improve the diagnostic accuracy of FNA biopsy. Epidermal growth factor receptor and ephrin B2 are markers of aggressive differentiated thyroid cancer.

The role of second opinion pathology in the management of lesions of the head and neck

PURPOSE OF REVIEW

Medical error is a common problem, and its human cost in terms of disability, suffering, and death is stunning. Steps toward reducing medical error will require the identification of mistake-prone practices within a complex health care system. Erroneous pathologic diagnosis has been identified as one source of error. This review was undertaken to assess the magnitude of diagnostic imprecision in lesions of the head and neck, and to address the validity of mandatory review of pathology material for patients who are referred from one institution to another for management of tumors involving the head and neck.

RECENT FINDINGS

Mandatory second opinion pathology consistently uncovers discrepancies across all major organ systems and has a profound impact on management and prognosis. Site-specific studies have implicated the head and neck as a high-risk area that is prone to diagnostic error. Diagnostic discrepancy rates have ranged from 1 to 53% for surgical pathology studies and from 17 to 60% for cytopathology studies. Major changes (affecting treatment or prognosis) occur in 5 to 7% of surgical pathology cases. The thyroid is consistently identified as a site that is particularly prone to diagnostic discrepancies; and no specific head and neck sites are immune to diagnostic error.

SUMMARY

Limited studies addressing the site-specific impact of second opinion pathology implicate the head and neck as a high-risk area that is prone to major changes in diagnoses. Accordingly, mandatory second opinion pathology makes good clinical and risk management sense for all patients referred to head and neck surgery or oncology services before a major therapeutic endeavor is undertaken.

Standards, Options et Recommandations 2004 pour une bonne pratique de la consultation personnelle et de la relecture en anatomie et cytologie pathologiques en cancérologie (rapport intégral)

CONTEXT

The "Standards, Options and Recommendations" (SOR) project, which started in 1993, is a collaboration between the French Federation of Cancer Centres (FNCLCC), the 20 French Regional Cancer Centres, and specialists from French public universities, general hospitals and private clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and the outcome of cancer patients.

OBJECTIVE

To develop good practice guidelines for second opinion in anatomic and surgical pathology in oncology, in collaboration with the French Society for Anatomic and Surgical Pathology.

METHOD

The methodology is based on a literature review and critical appraisal by a multidisciplinary group of experts who define the CPGs using the definitions of the Standards, Options and Recommendations project. Once the guideline has been defined, the document is submitted to independent reviewers for review.

RESULTS

The working group defined four types of second opinions in anatomic and surgical pathology: personal consultation, inter-institutional consultation, peer review consultation for a scientific survey, intra-departmental consultation in the context of quality control. The main recommendation is that second opinion should respect the patients' rights and the medical ethics code. For each of the four situations defined recommendations have been developed, taking this principle into consideration.

[Diagnosis of thyroid nodule. Application of evidence-based medicine]

OBJECTIVE

The frequency of thyroid nodules requires an appropriate and consistent undertaking of such pathology by the entire medical profession. Over the past few years, the ANAES (National Agency of Health Accreditation and Evaluation - 1995 - 1997) had formulated medical recommendations. Our work aimed at updating such recommendations considering recent literature developments and their level of evidence.

MATERIAL AND METHODS

We have selected high-level of evidence's articles published since 1997 dealing with the diagnostic undertaking of thyroid nodule. Such analysis was conducted using the search engine "Medline" and the level of evidence of the selected articles was evaluated by taking into account the professional recommendations of the "literature analysis and gradation of recommendations' guide" of ANAES.

RESULT

At present, two diagnostic tests are necessary in the diagnostic evaluation of a thyroid nodule (ultrasonography and fine-needle aspiration).

CONCLUSION

The medical recommendation will hence result in the synthesis of these two different diagnostic tests, nevertheless fine-needle aspiration being essential and having priority in evaluating the risk of cancer.

Utility of fine-needle aspiration for diagnosis of carcinoma associated with multinodular goitre

BACKGROUND

Fine-needle aspiration (FNA) is a useful method for evaluating a solitary thyroid nodule; however, this is not an agreed method for a multinodular goitre (MNG). The aim of this study was to assess the utility of preoperative FNA for detecting malignancy in MNG.

PATIENTS AND METHOD

We analysed operated MNGs in which FNA had been performed. Puncture was carried out on the dominant nodule and any other nodules with features suggesting malignancy. The diagnosis was classed as colloid, follicular or Hurthle proliferation, suggestive of malignancy, haematic and inadequate. The thyroid FNA results, grouped into suggestive of malignancy (positive result) and other diagnoses (negative result), were compared to those of the final histological study in order to calculate the value of the test in diagnosing malignancy.

RESULTS

FNA was performed in 432 MNGs, of which 42 (9.7%) were associated with carcinoma. Overall, the results of the test were poor, revealing a sensitivity of 17%, specificity of 96% and diagnostic accuracy of 88%, with a positive predictive value of 32% and negative predictive value of 88%. When the values were recalculated with the exclusion of microcarcinomas--considering their minor clinical importance--there was a slight improvement in the results: the sensitivity increased to 26%, diagnostic accuracy to 93% and negative predictive value to 96%. However, the specificity remained at 96%, and the positive predictive value fell from 32% to 25%. The results of the test improved in multifocal carcinomas.

CONCLUSIONS

Thyroid fine needle aspiration is not useful for differentiating MNG with malignant degeneration from benign MNG, as more than 80% of carcinomas go unnoticed; it provides a sensitivity of 17% for detecting carcinomas, rising to 26% if microcarcinomas are excluded. We therefore suggest that clinical criteria should prevail over FNA.

Fine-Needle Aspiration of Thyroid Nodules: Past, Present, and Future

OBJECTIVE

To present a review of the traditional and more recent techniques and applications of thyroid fine-needle aspiration biopsy.

METHODS

We describe the cytologic features and differential diagnoses of various thyroid lesions, outline recommendations for diagnostic categories, and discuss new techniques that have shown some promise in the diagnosis of thyroid nodule fine-needle aspiration specimens.

RESULTS

Fine-needle aspiration biopsy of the thyroid has proved to be an excellent diagnostic tool in the initial management of thyroid nodules. Numerous studies have shown its high sensitivity and specificity in diagnosing malignant tumors of the thyroid, especially papillary thyroid carcinoma. As with other diagnostic tests, however, its effectiveness is highly dependent on the expertise of the operator performing the procedure and the adequacy of the specimen for interpretation of the cytomorphologic features. On-site evaluation of thyroid specimens promotes adequate specimen sampling and reduces the incidence of nondiagnostic specimens. Diagnostic reports on thyroid fine-needle aspiration should include patient demographics and pertinent clinical history, site and size of the thyroid nodule, mode of aspiration, number of needle passes, assessment of specimen adequacy, diagnosis, and recommendations. Although immunohistochemical and molecular markers have received considerable attention recently, additional studies are needed before they can be used to separate benign from malignant follicular thyroid lesions.

CONCLUSION

Overall, fine-needle aspiration biopsy of thyroid nodules has proved to be sensitive, specific, and well accepted by patients because of minimal discomfort and complications.

Evidence-based criteria for adequacy in thyroid fine-needle aspiration

To determine whether some thyroid fine-needle aspirates classified as nondiagnostic correlate with benign thyroid nodules and can be distinguished from other nondiagnostic aspirates, I reviewed (from a total of 1,581) 80 nondiagnostic cases, all of which were hypocellular and lacked colloid, and correlated the cytologic findings with the results of pathologic follow-up. Of the 80, 16 had carcinoma at follow-up and 64 were benign. The cellularity of the carcinoma cases ranged from 0 to 100 cells (mean, 20 cells), but every case with epithelial cells had Hürthle cell change or atypia suggestive of papillary carcinoma. The cellularity of the 64 benign cases ranged from 0 to 120 cells (mean, 40 cells), 17 of which had Hürthle cell change. There were 25 cases with at least 10 benign-appearing follicular cells without atypia or Hürthle cell change; all 25 cases were associated with benign follow-up. While these results need to be confirmed by others, the evidence suggests that a proportion of thyroid aspirates that do not meet traditional criteria for adequacy still may be associated strongly with a benign thyroid nodule and can be distinguished from other nondiagnostic aspirates.