2018-19 Section 7-Neoplastic and Inflammatory Diseases of the Head and Neck eBook

Reprinted by permission of Acta Cytol. 2017; 61(3):187-193.

Fine Needle Aspiration

Acta Cytologica 2017;61:187–193 DOI: 10.1159/000469654

Received: March 8, 2017 Accepted after revision: March 9, 2017 Published online: April 27, 2017

Impact of the Reclassification of the Non-Invasive Follicular Variant of Papillary Carcinoma as Benign on the Malignancy Risk of the Bethesda System for Reporting Thyroid Cytopathology: A Meta-Analysis Study

a Zubair W. Baloch

b Magda Esebua

a Rohini Kannuswamy a

Lester J. Layfield Robert L. Schmidt c

a Department of Pathology and Anatomical Sciences, University of Missouri, Columbia, MO, b Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, and c Department of Pathology and Laboratory Medicine and ARUP Laboratories, University of Utah, Salt Lake City, UT, USA

Keywords Meta-analysis · Bethesda System for Reporting Thyroid Cytopathology · Malignancy risk

considered benign. A meta-analysis of malignancy risk data for the 3 published studies and the current study was per- formed. Results: The meta-analysis showed that the malig- nancy risk was reduced for all TBSRTC categories except the “non-diagnostic” category. The reduction in malignancy risk was greatest in the categories “suspicious for malignancy” and “atypia/follicular lesion of undetermined significance.” Conclusion: A meta-analysis of all pertinent studies demon- strated that re-categorization of the non-invasive follicular variant of papillary thyroid carcinoma as benign reduces the malignancy risk in the majority of TBSRTC categories. © 2017 S. Karger AG, Basel

Abstract Objectives: The Bethesda System for Reporting Thyroid Cy- topathology (TBSRTC) established diagnostic categories for cytologic specimens of the thyroid. Each category was asso- ciated with an estimated risk of malignancy. Recently, the non-invasive follicular variant of papillary thyroid carcinoma has been reclassified as benign. This reclassification may al- ter the malignancy risk of TBSRTC diagnostic categories. Study Design: A literature search was made for all studies investigating the effect of reclassification of some non-inva- sive follicular variant papillary thyroid carcinomas as benign on the malignancy risk associated with TBSRTC categories. The authors calculated the malignancy risk for TBSRTC cat- egories in a series of 315 thyroid aspirates when the non- invasive follicular variant of papillary thyroid carcinoma was

Introduction

The Bethesda System for Reporting Thyroid Cytopa- thology (TBSRTC) was designed as a comprehensive ap- proach to the reporting of thyroid cytopathology [1] . The Bethesda guidelines included recommendations for crite-

Correspondence to: Prof. Lester J. Layfield Department of Pathology and Anatomical Sciences, University of Missouri One Hospital Drive, M263 Medical Sciences Building Columbia, MO 65212 (USA) E-Mail layfieldl@health.missouri.edu

© 2017 S. Karger AG, Basel

E-Mail karger@karger.com www.karger.com/acy

128