The National Cancer Institute Thyroid Fine-Needle Aspiration State-of-the-Science Conference

Abstract

T hyroid fine-needle aspiration (FNA) is a modern-day success story. Its clinical value is undisputed-safely and rapidly, FNA provides valuable information about the nature of a thyroid nodule and permits the triage of patients for follow-up or surgery. Because thyroid nodules are so common, in many laboratories, thyroid FNA has become the most common FNA specimen examined.Our colleagues in endocrinology, surgery, and radiology have already successfully addressed professional consensus on the clinical aspects of thyroid FNA. In 2005 and 2006, they sponsored consensus conferences to develop guidelines that address the clinical questions surrounding thyroid nodules: How big should a thyroid nodule be before it is aspirated? What sonographic features should prompt an FNA? How should patients be managed when they have a benign, suspicious, or malignant thyroid FNA result? Debate on these issues, grounded in peer-reviewed data, resulted in published consensus statements that now serve as valuable clinical management resources. [1][2][3][4] But how about agreement on cytology-related issues, say, terminology for reporting the results of thyroid FNA? To date, nationally (and internationally), there has been no consensus on reporting thyroid FNA results. Some laboratories have used a modification of traditional cytology diagnostic categories (negative, suspicious, positive), 5-7 whereas others have dispensed with categories and relied on descriptive phrases. Understandably, such lack of uniformity creates a challenge for our clinical colleagues, who often are at a loss to understand a cytology report, particularly one from an unfamiliar laboratory that uses unfamiliar terminology. It goes without saying that confusion over the meaning of a thyroid FNA report may seriously harm a patient if thyroid surgery is undertaken or withheld inappropriately. Now, we in cytology can proudly say that we have caught up with our clinical colleagues, and in a big way.

MicroRNA Signature in Thyroid Fine Needle Aspiration Cytology Applied to “Atypia of Undetermined Significance” Cases

“…Using the miR-LDA method to classify atypia FNA cases into high-risk and low-risk categories FNA cytology classified all the specimens into atypia, follicular neoplasm, suspicious, or malignant categories according to the Bethesda system for thyroid cytology (Supplementary Tables S1 and S2) (8). To evaluate the potential use of the miR-LDA predictions for the atypia FNA cases, we classified the cases predicted as malignant into high risk and those predicted as benign into low-risk categories (Table 3).…”

“…Common histologic diagnoses that may present cytologically as follicular lesions include nodular hyperplasia (NH), follicular adenoma (FA), follicular variant of Departments of 1 Pathology, 3 Molecular Virology, Immunology, and Medical Genetics, and papillary thyroid carcinoma (fvPTC), and follicular thyroid carcinoma (FTC). In 2007, the National Cancer Institute Thyroid FNA State of the Science Conference (http:// thyroidfna.cancer.gov) proposed new classification criteria and terminology for thyroid FNA (8). Thyroid lesions are categorized as benign, atypia (of undetermined significance), follicular neoplasm, suspicious, and malignant (8,9).…”

“…In 2007, the National Cancer Institute Thyroid FNA State of the Science Conference (http:// thyroidfna.cancer.gov) proposed new classification criteria and terminology for thyroid FNA (8). Thyroid lesions are categorized as benign, atypia (of undetermined significance), follicular neoplasm, suspicious, and malignant (8,9). The category of atypia includes a group of heterogeneous FNA cases, with an estimated risk of malignancy of 5-15%, although higher rates of malignancy have been reported (10,11).…”

Spectrum of Risk of Malignancy in Subcategories of ‘Atypia of Undetermined Significance’

“…In order to provide standard and reliable diagnostic information for the increased numbers of thyroid FNAs, there was a need to address the historical confusion surrounding the appropriate reporting of uncertain findings [9] and the acceptance and validation of risk categories. This led to a National Cancer Institute (NCI) State of the Science Conference [10,11,12] which resulted in The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) [13,14,15]. …”

Predictors of malignancy in thyroid fine‐needle aspirates “cyst fluid only” cases

“…Possibly, quality control benchmarks could be developed for this interpretive category. 7 The amount of colloid, number of macrophages and pigment-laden macrophages, and amount of blood and inflammatory cells were not found to be predictive of a malignant histologic outcome. The sole morphologic feature of malignancy was the presence of atypical features in follicular epithelium, if present.…”