Comparison of Diagnostic Rates and Concordance with Subsequent Surgical Resections between Conventional Smear and ThinPrep Preparations versus ThinPrep Only in Thyroid Fine Needle Aspiration (T-FNA) Specimens

<b><i>Background:</i></b> Thyroid fine needle aspiration (T-FNA) is a mainstay in management of thyroid nodules. However, the preparation of T-FNA specimens varies across institutions. Prior studies have compared diagnostic rates between different specimen preparations of T-FNA specimens and their associated advantages and disadvantages. However, few have compared the rates of all diagnostic categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) between liquid-based preparations (LBPs) and a combination of LBP and conventional smear (CS) preparations. Our study compares TBSRTC diagnostic rates between these 2 cohorts and correlates cytologic diagnoses with subsequent thyroid resections to evaluate rates of neoplasia (RON) and malignancy (ROM). <b><i>Methods:</i></b> 584 consecutive thyroid FNA specimens were collected and stratified by preparation type (ThinPrep [TP] vs. CS &amp; TP). Diagnostic rates for each TBSRTC diagnostic category were calculated. The institution’s electronic medical records database was searched for histologic diagnoses of previously sampled thyroid nodules to evaluate the RON and ROM. <b><i>Results:</i></b> Of 584 thyroid FNA specimens, 73 (12.5%) and 511 (87.5%) were evaluated by TP only and CS &amp; TP, respectively, reflecting the predominance of rapid on-site evaluation (ROSE) with CS for T-FNAs at our institution. Of the TP only and CS &amp; TP cohorts, 29 (39.7%) and 98 (19.2%) had subsequent resections, respectively. The frequency of non-diagnostic cases was lower in the CS &amp; TP cohort (12.7% vs. 26%). While the diagnostic rate of follicular lesion of undetermined significance was similar for both cohorts, SFN categorization was only utilized in the CS &amp; TP cohort (1.5% vs. 0%). Although RON and ROM were similar between cohorts in many of the TBSRTC categories, there was a higher RON associated with non-diagnostic specimens in the TP only cohort when the denominator included all non-diagnostic cases. <b><i>Conclusion:</i></b> The combination of CS and LBP may potentially decrease the non-diagnostic rate of T-FNA specimens as well as the number of passes required for diagnosis, particularly with ROSE. Evaluation of morphologic features highlighted in conventional smears may facilitate diagnostic categorization in the “suspicious for follicular neoplasm” category.

Interpretive Errors in Fine-Needle Aspiration of Thyroid: A 13-Year Institutional Experience in Lebanon

<b><i>Introduction:</i></b> Fine-needle aspiration (FNA) is a worldwide established diagnostic tool for the assessment of patients with thyroid nodules. All thyroid FNA interpretive errors (IEs) were reviewed at the American University of Beirut Medical Center over a 13-year period, in order to identify and analyze them. <b><i>Materials and Methods:</i></b> All FNAs and their corresponding pathology results are correlated yearly for quality assurance. Discrepant cases are segregated into sampling errors and IEs. All thyroid FNAs with IEs were collected from 2005 to 2017. FNA and pathology slides were reviewed by trained, board-certified cytopathologists, adhering to the latest Bethesda criteria. Reasons for erroneous diagnoses were studied. <b><i>Results:</i></b> There was a total of 11 IEs out of 340 thyroid FNAs followed by surgical resection. Five benign follicular nodules (BFNs) were misinterpreted as suspicious for carcinoma. Focal nuclear atypia in cyst-lining or follicular cells and a monotonous population of macrophages misinterpreted as Hurthle cells (HCs) were the causes of IEs in this category. Four Hashimoto’s thyroiditis (HT) cases were misinterpreted as suspicious for malignancy. Innate atypia of HCs and sampling misinterpretation were the causes of IEs in HT. One medullary and 1 follicular carcinoma were misinterpreted as suspicious for follicular neoplasm and BFN, respectively. Nine cases were better classified after review. <b><i>Conclusion:</i></b> Thyroid FNA IEs can be mitigated by meticulous screening and identification of all elements on FNA smears. Awareness of focal nuclear atypia in reactive cyst-lining and follicular cells in BFN, as well as HCs in HT, is highlighted. Adherence to The Bethesda System for Reporting Thyroid Cytopathology and consulting experienced cytopathologists significantly decrease IEs.

Molecular Testing of Thyroid Fine-Needle Aspiration: Local Issues and Solutions. An Interventional Cytopathologist Perspective

Molecular testing has acquired a relevant role for diagnostic and prognostic stratification of indeterminate thyroid nodules. Besides the available commercial solutions marketed in the United States, various local testing strategies have been developed in the last decade. In this setting, the modern interventional cytopathologist, the physician who performs the both aspirate and the morphologic interpretation plays a key role in the correct handling of fine-needle aspiration (FNA) samples not only for microscopy but also for molecular techniques. This review summarizes experiences with local approaches to the molecular testing of thyroid FNA, highlighting the role of the modern interventional cytopathologist.

Comparison of Ultrasound-Guided Fine-Needle Cytology Quality in Thyroid Nodules with 22-, 23-, and 25-Gauge Needles

Objective. To compare the cytology quality of ultrasound-guided fine-needle biopsy in thyroid nodules with 22-, 23-, and 25-gauge (G) needles prospectively. Methods. A total of 240 consecutive nodules underwent ultrasound-guided fine-needle aspiration (USG-FNA) and 240 nodules underwent ultrasound-guided fine-needle capillary (USG-FNC) were included in this prospective study from October 2014 to February 2016. Each nodule was sampled using 22 G, 23 G, and 25 G needle according to designed orders, and 1240 smears were finally obtained. Cytology quality was scored by a cytologist blinded to needle selection. Results. In USG-FNA, the average scores and standard deviations were 5.50 ± 2.87 for 25 G needles, 4.82 ± 2.95 for 23 G needles, and 5.19 ± 2.81 for 22 G needles. In USG-FNC, the average scores and standard deviations of each group were 5.12 ± 2.69 for 25 G, 4.60 ± 2.90 for 23 G, and 4.90 ± 2.90 for 22 G needles. The specimen quality scores of 25 G group were significantly higher than that of 23 G group ( P < 0.017 ) in both USG-FNA and USG-FNC. However, the differences were not statistically significant in nondiagnostic rate using different gauge of needles ( P > 0.017 for all). Conclusions. 25 G needles obtained the highest scores of sample quality in thyroid FNA and FNC comparing with 22 G and 23 G needles. 25 G needle should be first choice of thyroid FNA and FNC in routine work.

NTRK, RET, BRAF, and ALK fusions in thyroid fine-needle aspirates (FNAs).

6083 Background: Receptor tyrosine kinase (RTK) fusions may be targeted by small molecule inhibitors to treat various advanced tumors, including thyroid cancer. Clinical trials have studied selective inhibitors of ALK, BRAF, NTRK and RET, leading to several FDA-approved therapies. The Afirma Genomic Sequencing Classifier (GSC) classifies cytologically indeterminate thyroid nodules as molecularly benign or suspicious. The Xpression Atlas reports 905 genomic variants and 235 fusion pairs on GSC Suspicious, Suspicious for Malignancy (SFM), and Malignant FNA samples at the time of diagnosis. Here we report the prevalence of these fusion genes in real-world clinical practice. Methods: We analyzed anonymized data from 50,644 consecutive Bethesda III-VI nodule FNA samples submitted to the Veracyte CLIA laboratory for molecular testing using whole transcriptome RNA sequencing (RNA-Seq). Gene pairs are listed alphabetically. Results: 32,080 Bethesda III/IV nodules were classified as GSC Benign and 278 were Parathyroid Classifier positive. No ALK, BRAF, NTRK1/3, or RET fusions were identified among these samples. Among 16,594 Bethesda III/IV GSC Suspicious FNAs, 3% (n = 529) were positive for ALK, BRAF, NTRK1/3 or RET fusions. Among the 1,692 Bethesda V/VI FNAs, the proportion of positive nodules was 8% (n = 135). Among these combined cohorts of Bethesda III/IV GSC Suspicious and Bethesda V/VI, the most common gene fusions observed for each of the 5 studied RTK genes was: ETV6/NTRK3 (n = 164, 72% of NTRK3 fusions), CCDC6/RET (n = 104, 55% of RET), BRAF/SND1 (n = 32, 20% of BRAF), ALK/STRN (n = 20, 37% of ALK), and NTRK1/TPM3 (n = 14, 50% of NTRK1). BRAF showed the highest diversity of fusions, with 80 gene partners. Different gene partners with RET, ALK, NTRK1, and NTRK3 numbered 25, 11, 9, and 5 , respectively . Conclusions: Whole-transcriptome RNA-seq on small sample thyroid FNA specimens can identify clinically relevant ALK, BRAF, NTRK, and RET fusions across Bethesda categories. The prevalence ranges from 3% in Bethesda III/IV Afirma GSC Suspicious specimens to 8% among Bethesda V/VI specimens. Future studies need to determine if detection of precision medicine candidates by pre-operative FNA can optimize initial treatment, predict response to treatment, and prioritize selective targeted therapy should systemic treatment be needed.[Table: see text]

Endovascular treatment of massive hemorrhage arising from inferior thyroid artery after fine needle aspiration of thyroid: a case report

Background Fine needle aspiration (FNA) of the thyroid gland is an effective and safe method for evaluating thyroid nodules; catastrophic complications following FNA of thyroid are rare. Massive hematomas with active bleeding leading to airway compromise are extremely rare complications of FNA, with only a few reported cases in literature. Case presentation An 80 year-old man presented to the emergency room with severe respiratory distress, four hours after undergoing thyroid FNA for the evaluation of a thyroid nodule. An axial neck computed tomography (CT) revealed a large hematoma in the retropharyngeal space that caused anterior deviation of the trachea, with extravasation of contrast media suggesting active bleeding within the hematoma. Right subclavian angiography identified active bleeding from the right inferior thyroid artery (ITA). Transcatheter arterial embolization (TAE) was successfully performed with n-Butyl cyanoacrylate (NBCA). Follow-up CT done three weeks after the procedure revealed a low-density lesion in the retropharyngeal space, indicating an old hematoma. The patient recovered well and was discharged 6 weeks later. Conclusion Massive hemorrhage arising from the ITA is a rare but possible complication following FNA, which can potentially be fatal. Appropriate preventive measures should be taken while performing FNA, especially in patients on long-term anticoagulant drugs, and prompt intervention is mandatory for patients with acute hematoma after FNA.