Thyroid 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.1–4
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. Thanks to the leadership of Dr. Andrea Abati, Chief of Cytopathology at the National Cancer Institute (NCI), in 2007, the NCI sponsored the “NCI Thyroid FNA State-of-the-Science Conference” (NCI Thyroid Conference), a multidisciplinary conference that took place in Bethesda, Maryland on October 22 and 23, 2007, with an accompanying website (http://thyroidfna.cancer.gov). In scope, the agenda was very ambitious, addressing indications, training, techniques, terminology for reporting results, ancillary testing, and management guidelines: quite an undertaking for a 2-day conference! What made it work was the effort put into draft documents before the meeting and the long comment periods that occurred online before the conference, in the spring and summer months of 2007, as well as for a brief period afterward.
The final summary documents from this conference will provide a valuable resource, particularly on cytology-related matters. Like a pebble thrown into a lake, the NCI Thyroid Conference will have a ripple effect. The “Review and Conclusions” documents posted on the website, as well as the published conference proceedings, summarize the state of the art with regard to terminology and other issues. A Bethesda System-type diagnostic framework for reporting thyroid FNA results is in the planning stages and will emerge soon in the forms of a web and print atlas, both offshoots of the NCI Thyroid Conference and very much inspired by it. For clarity of communication and the ability to share data across institutions, the Bethesda thyroid FNA framework will be organized around a limited number of diagnostic categories. The categories will be tied to rational, evidence-based management algorithms. Criteria will be outlined and illustrated for each category. Quality-control benchmarks will be provided to assist laboratories in monitoring the frequency with which categories are used and their expected histologic outcomes, based on published literature.
The NCI Thyroid Conference addressed a wide range of issues other than terminology. The meeting highlighted the growing body of data supporting the value of ultrasound guidance for thyroid FNA without discarding the usefulness of directed aspirations for clearly palpable, solid lesions. An exchange of ideas regarding sample preparation types (smears vs liquid based) took place both at the meeting and in the online discussion forums.6, 8–10 Keen proponents of both techniques are practicing cytopathology successfully and extolled the virtues of each in both venues.
The success of the conference derived from the participation of a multidisciplinary group of healthcare professionals with a commitment to improving care for patients with thyroid nodules. Conclusions made by committee often are derided as suboptimal compromises (Sir Alec Issigonis has been credited with the comment that a camel is a horse designed by committee). However, in this case, the bringing together of cytopathologists, surgical pathologists, endocrinologists, radiologists, and surgeons provided a heady mix for debate and the exchange of ideas. There was much talk afterward about the palpable benefits of this interdisciplinary approach. Each specialty helped to shine light on the issues discussed. And the representation by multiple disciplines threw into relief the need for clarity of communication and a common language. It is remarkable how important a multidisciplinary approach can be for the success of a venture. The cytology profession has made strong efforts in the past to develop a common framework for thyroid FNA terminology.11 The fact that such attempts were unidisciplinary may explain in part why they did not find wide application.
The adoption of a uniform framework for thyroid FNA terminology promises to be a significant advance in the care we provide our patients. It will improve communication and facilitate the exchange of data. It will help coordinate the teaching of thyroid cytology to our cytotechnologists and pathologists in training. It will inspire multi-institutional studies of promising molecular tests to help triage inconclusive results. And, like the Bethesda System for gynecologic cytology, it probably will be modified and refined over the years as experience with the terminology accrues and the semantic issues are clarified.