The Bethesda System For Reporting Thyroid Cytopathology

Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Thyroid: official journal of the American Thyroid Association (Impact Factor: 4.49). 11/2009; 19(11):1159-65. DOI: 10.1089/thy.2009.0274
Source: PubMed


To address terminology and other issues related to thyroid fine-needle aspiration (FNA), the National Cancer Institute (NCI) hosted The NCI Thyroid FNA State of the Science Conference. The conclusions regarding terminology and morphologic criteria from the NCI meeting led to the Bethesda Thyroid Atlas Project and form the framework for the Bethesda System for Reporting Thyroid Cytopathology.
Participants of the Atlas Project were selected from among the committee members of the NCI FNA State of the Science Conference and other participants at the live conference. The terminology framework was based on a literature search of English language publications dating back to 1995 using PubMed as the search engine; online forum discussions ( ); and formal interdisciplinary discussions held on October 22 and 23, 2007, in Bethesda, MD.
For clarity of communication, the Bethesda System for Reporting Thyroid Cytopathology recommends that each report begin with one of the six general diagnostic categories. Each of the categories has an implied cancer risk that links it to an appropriate clinical management guideline.
The project participants hope that the adoption of this framework will facilitate communication among cytopathologists, endocrinologists, surgeons, and radiologists; facilitate cytologic-histologic correlation for thyroid diseases; facilitate research into the understanding of thyroid diseases; and allow easy and reliable sharing of data from different laboratories for national and international collaborative studies.

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    • "A 25-gauge needle was typically used to obtain three samples per nodule , and FNA cytology was evaluated by a Brigham and Women's Hospital cytopathologist. Although much of the study predates the Bethesda System for Reporting Thyroid Cytopathology[15,16], all Brigham and Women's Hospital cytopathologists were already using identical criteria later adopted by the Bethesda System for Reporting Thyroid Cytopathology. All thyroid FNAs were classified into one of the following categories: non-diagnostic, negative for malignant cells (benign), atypical cells of undetermined significance (AUS), suggestive of a follicular or Hurthle cell neoplasm, suspicious for malignancy, or positive for malignancy . "
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    ABSTRACT: Background Thyroid nodules are common, and most are benign. Given the risk of false-negative cytology (i.e. malignancy), follow-up is recommended after 1–2 years, though this recommendation is based solely on expert opinion. Sonographic appearance may assist with planning, but is limited by large inter-observer variability. We therefore compared the safety and efficacy of long- versus short-interval follow-up after a benign initial aspiration, regardless of sonographic appearance. Methods This study evaluated all patients referred to the Brigham and Women’s Hospital Thyroid Nodule Clinic, between 1999 and 2010, with a cytologically benign nodule >1 cm and who had returned for follow-up sonographic evaluation. Despite standard clinical recommendations, variation in patient compliance resulted in variable follow-up intervals from time of initial aspiration to the first repeat evaluation. Main outcome measures included nodule growth, repeat fine needle aspiration (FNA), thyroidectomy, malignancy, and disease-specific mortality. Results We evaluated 1,254 patients with 1,819 cytologically benign nodules, with a median time to first follow-up of 1.4 years (range, 0.5–14.1 years). The longer the follow-up interval, the more nodules grew and the more repeat FNAs were performed (P <0.001). The most clinical meaningful endpoints of malignancy or mortality, however, did not differ between the various follow-up intervals. The risk of a thyroidectomy (usually because of compressive symptoms) increased when time to first follow-up exceeded >3 years (4.9 % vs. 1.2 %, P = 0.0001), though no difference in malignancy risk was identified (0.2–0.8 %, P = 0.77). No (0 %) thyroid cancer-specific deaths were identified in either cohort. Conclusions While expert opinion currently recommends repeat evaluation of a cytologically benign nodule at 1–2 years, these are the first data to demonstrate that this interval can be safely extended to 3 years without increased mortality or patient harm. Nodule growth can be expected, though detection of malignancies is unchanged. While replication of these data in large prospective multicenter studies is needed, this extension in follow-up interval would reduce unnecessary visits and medical interventions for millions of affected patients worldwide, leading to healthcare savings. Please see related commentary article: http:// dx. doi. org/ 10. 1186/ s12916-016-0559-9 and research article: http:// dx. doi. org/ 10. 1186/ s12916-015-0419-z.
    Full-text · Article · Dec 2016 · BMC Medicine
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    • "Laboratory for Cellular and Molecular Thyroid Research, Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA diagnostic challenge in clinical practice. Indeterminate thyroid cytology includes three categories—atypia of undetermined significance (AUS), follicular neoplasm (FN) and suspicious for malignancy[9]. Surgical treatment for thyroid nodules cytologically suspicious for malignancy is generally accepted because of its high preoperative malignancy probability (around 60–70 %) and the treatment decision seems to be relatively easy to make. "
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    ABSTRACT: RAS mutations play an important role in thyroid tumorigenesis. Considerable effort has been made in the last decade to apply RAS mutations as molecular markers to the clinical management of thyroid nodules and thyroid cancer. Yet, for the low diagnostic sensitivities and specificities of RAS mutations, when used alone, and for their uncertain role in the clinical outcomes of thyroid cancer, it has been unclear how to appropriately use them to assist the management of thyroid nodules and thyroid cancer. Studies from recent years, now added from the Alexander group, have shed light on this issue, making a blurred clinical picture now emerge clearer—RAS mutations, when combined with other genetic markers, have high diagnostic negative predictive values for thyroid cancer; cytologically benign thyroid nodules, including those positive for RAS mutations, have long-term clinical stability when non-surgically managed; and differentiated thyroid cancers harboring RAS mutations alone have an excellent prognosis. This progress in understanding RAS mutations in thyroid cancer is showing a major impact on molecular-based practice in the management of thyroid cancer. Please see related research articles: and
    Full-text · Article · Dec 2016 · BMC Medicine
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    • "Technically, FNAC and CNB cannot differentiate between benign and malignant FNs because their morphologies overlap inherently and it is not possible to assess capsular or vascular invasion in the FNAC and CNB specimens. Most patients who have nodules that fall in the FN category by FNAC or CNB undergo diagnostic lobectomy, which leads to a definitive diagnosis following histological examination [1,4,5,8,12,30]. Approximately 15–30% of cases with FN cytology are identified as malignant after surgery [1,4,9] . "

    Full-text · Dataset · Feb 2016
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