title: Insufficient experience in thyroid fine-needle aspiration leads to misdiagnosis of thyroid cancer.
abstract: BACKGROUND
  Fine-needle aspiration (FNA) of the thyroid is a widely accepted confirmatory test for thyroid cancer with high sensitivity and specificity. FNA is a simple procedure that is learned by many clinicians to enable accurate diagnosis of thyroid cancer. However, it is assumed that because the FNA test is a relatively simple procedure, its cytologic results are reliable regardless of the operator's experience. The aim of this study was to evaluate the differences in the diagnostic indices of FNA between operators with different levels of experience.
  
  
  METHODS
  A total of 694 thyroid FNA specimens from 469 patients were reviewed, and were separated based on the experience of the clinicians who performed the procedure. One hundred and ninety were categorized in the experienced group, and 504 in the inexperienced group. All FNA results were then compared with histological data from surgically resected specimens, and the sample adequacy and diagnostic accuracy of the groups were compared.
  
  
  RESULTS
  The age, gender, and nodule size and characteristics were similar in both groups. The sample adequacy rate was not significantly different between the experienced and nonexperienced groups (96.3% vs. 95.4%, P=0.682). However, the non-experienced group had a higher false-negative rate than the experienced group (6.4% vs. 17.2%, P=0.038), and the sensitivity of the FNA test also tended to be lower in the nonexperienced group (95.6% vs. 88.9%, P=0.065).
  
  
  CONCLUSIONS
  These results suggest that FNA operators who have less experience may miss cases of thyroid cancer by performing the procedure incorrectly. As such, the experience of the FNA operator should be considered when diagnosing thyroid cancer. When clinicians are being trained in FNA, more effort should be made to increase the accuracy of the procedure; therefore, enhanced teaching programs and/or a more detailed feedback system are recommended.
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Jung Il
authors.initials: JI
authors.lastname: Son
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sang Youl
authors.initials: SY
authors.lastname: Rhee
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Jeong-Taek
authors.initials: JT
authors.lastname: Woo
authors.affiliation: Department of Surgery, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Won Seo
authors.initials: WS
authors.lastname: Park
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Jong Kyu
authors.initials: JK
authors.lastname: Byun
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Ja Min
authors.initials: JM
authors.lastname: Byun
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sang Ouk
authors.initials: SO
authors.lastname: Chin
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Suk
authors.initials: S
authors.lastname: Chon
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Seungjoon
authors.initials: S
authors.lastname: Oh
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sung Woon
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Young Seol
authors.initials: YS
authors.lastname: Kim
keywords: Biopsy, fine-needle; Diagnosis; Diagnostic errors; Thyroid neoplasms