Cytohistologic Correlation of Thyroid Lesions: The Effect of the Bethesda System for Reporting Thyroid Cytopathology
Feriyl Bhaijee, Kathryn Brown, Israh Akhtar, Anwer Siddiqi. University of Mississippi Medical Center, Jackson, MS
Background: Fine needle aspiration (FNA) is commonly used in the evaluation of thyroid pathology. This study correlates thyroid FNA cytology results with subsequent histopathologic diagnoses and compares correlation rates pre- and post- implementation of the Bethesda System for Reporting Thyroid Cytopathology.
Design: We reviewed all thyroid FNAs performed at a large academic medical center between 01/2006 and 09/2011 and identified patients that underwent subsequent surgical resection. The Besthesda System for Reporting Thyroid Cytopathology was implemented in 2010.
Results: Over a 5.75 year period, 156 patients underwent thyroid FNA and subsequent resection. Overall, cytohistologic correlation was achieved in 73% (114/156) of patients. Of the 42 cases with cytohistologic disparity: 15 follicular adenomas were called benign(7), suspicious for papillary thyroid carcinoma (PTC)(4), or unsatisfactory(4) on preceding FNA; 10 PTCs were called benign(2), AUS/FLUS(2), follicular neoplasm(3), or unsatisfactory(3); 13 benign lesions were called FLUS(1), suspicious for follicular neoplasm(1), follicular neoplasm(1), suspicious for PTC(3), or unsatisfactory(7); 2 follicular carcinomas were called either FLUS or benign; 1 poorly-differentiated carcinoma was called medullary carcinoma; and 1 leiomyosarcoma was unsatisfactory on FNA.
Cytohistologic correlation pre- and post-Bethesda implementation was 71% (77/109) and 79% (37/47), respectively. Pre-implementation, 32 cases showed cytohistologic disparity: 8 cases called benign on FNA showed follicular adenoma(6), follicular carcinoma(1), or PTC(1) on subsequent resection; 12 unsatisfactory FNAs were benign(5), follicular adenoma(4), or PTC(3); 4 cases called follicular neoplasm were PTC(3) or benign(1); 1 case called suspicious for follicular neoplasm was benign; and 7 cases called suspicious for PTC were follicular adenoma(4) or benign(3). Post-Bethesda implementation, 10 cases showed disparity: 2 cases called benign on FNA showed either follicular adenoma or PTC on subsequent resection; 3 unsatisfactory FNAs were benign(2) or leiomyosarcoma(1); 4 AUS/FLUS on FNA were follicular carcinoma(1), PTC(2), or benign(1); and 1 case called medullary carcinoma on FNA showed poorly-differentiated carcinoma histologically.
Conclusions: Thyroid FNA cytology and subsequent histopathologic diagnoses correlate well overall, with modest improvement post-Bethesda implementation. In our setting, the high prevalence of thyroid pathology and the well-defined Bethesda criteria thereof will likely further improve cytohistologic correlation rates over time.
Category: Quality Assurance
Monday, March 19, 2012 1:00 PM
Poster Session II # 260, Monday Afternoon