title: False-negative results with the Bethesda System of reporting thyroid cytopathology: predictors of malignancy in thyroid nodules classified as benign by cytopathologic evaluation.
abstract: The benign category of the Bethesda System for reporting thyroid cytopathology (BSRTC) predicts an incidence of malignancy from zero to three per cent. However, recent series report higher rates of malignancy ranging from eight to 14 per cent. Surgery is often performed for reasons other than their fine needle aspiration biopsy (FNAB) such as symptoms, nodule enlargement, or worrisome imaging. We hypothesized that an analysis of patients who underwent thyroidectomy despite a benign FNAB would identify predictors of malignancy, an area not currently addressed by American Thyroid Association guidelines. We performed a retrospective analysis of patients with benign FNAB results who underwent thyroidectomy from October 2007 to October 2012. Data collected included symptoms, imaging findings, FNAB results, and operative and histopathology results, all of which were obtained by chart review. Findings were compared between patients with and without a diagnosis of malignancy. Statistical significance was set as P < 0.05. Of 3839 FNABs, 2838 were benign. Of these, 180 underwent surgery for indications other than the FNAB category. Twenty-four (13.4%) malignancies were identified: 12 (6.7%) incidental microcarcinomas and 12 (6.7%) significant cancers (papillary greater than 1.0 cm, any nonpapillary histology). No patient's symptoms or signs reached significance as a predictor of malignancy. Suspicious ultrasound appearance was significantly associated with an underlying carcinoma (P = 0.004). The false-negative result with benign FNAB is higher in surgical series than suggested by the BSRTC. Patients with tolerable symptoms may be observed in the face of a benign FNAB. Additionally, despite a benign FNAB, recommendations for closer follow-up or surgical intervention are warranted if the ultrasound appearance is suspicious.
authors.affiliation: Department of Surgery, West Virginia University/Charleston Division, Charleston, West Virginia, USA.
authors.forename: Bryan K
authors.initials: BK
authors.lastname: Richmond
authors.forename: Rudy
authors.initials: R
authors.lastname: Judhan
authors.forename: Benny
authors.initials: B
authors.lastname: Chong
authors.forename: Adam
authors.initials: A
authors.lastname: Ubert
authors.forename: Zachary
authors.initials: Z
authors.lastname: AbuRahma
authors.forename: William
authors.initials: W
authors.lastname: Mangano
authors.forename: Stephanie
authors.initials: S
authors.lastname: Thompson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D003581:Cytodiagnosis; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D016606:Thyroid Nodule / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy
references.citation: Surgery. 2010 Dec;148(6):1313-5
references.pmid: 21134567
references.citation: Endocr Pract. 2013 May-Jun;19(3):444-50
references.pmid: 23337148
references.citation: Endocr Pract. 2006 Jan-Feb;12(1):63-102
references.pmid: 16596732
references.citation: Thyroid. 2009 Nov;19(11):1159-65
references.pmid: 19888858
references.citation: Surgery. 2011 Dec;150(6):1234-41
references.pmid: 22136846
references.citation: World J Surg. 1986 Oct;10(5):781-6
references.pmid: 3776215
references.citation: Cancer. 2007 Oct 25;111(5):306-15
references.pmid: 17680588
references.citation: Diagn Cytopathol. 2013 Oct;41(10):858-63
references.pmid: 23512999
references.citation: Am Surg. 2012 Jun;78(6):706-10
references.pmid: 22643269
references.citation: Ann Surg Oncol. 2012 May;19(5):1472-6
references.pmid: 21969084
references.citation: Surgery. 1995 Dec;118(6):996-1003; discussion 1003-4
references.pmid: 7491545
references.citation: Surgery. 2007 Dec;142(6):837-44; discussion 844.e1-3
references.pmid: 18063065
references.citation: Ann Intern Med. 2005 Jun 7;142(11):926-31
references.pmid: 15941700
references.citation: Thyroid. 2009 Nov;19(11):1167-214
references.pmid: 19860577
references.citation: Cancer Cytopathol. 2010 Aug 25;118(4):190-5
references.pmid: 20586117
references.citation: Endocrinol Metab Clin North Am. 1990 Sep;19(3):509-22
references.pmid: 2261905
references.citation: QJM. 2007 Jan;100(1):29-35
references.pmid: 17178736