title: Does Tumor Size Influence the Diagnostic Accuracy of Ultrasound-Guided Fine-Needle Aspiration Cytology for Thyroid Nodules?
abstract: Background. Fine-needle aspiration cytology (FNAC) is diagnostic standard for thyroid nodules. However, the influence of size on FNAC accuracy remains unclear especially in too small or too large thyroid nodules. The objective of this retrospective cohort study was to investigate the effect of nodule size on FNAC accuracy.Methods.All consecutive patients who underwent thyroidectomy for nodules in 2010 were enrolled. FNAC results (according to the Bethesda system) were compared to pathological diagnosis. The nodules were categorized into groups A-E on the basis of maximal diameter on ultrasound (≤0.5, >0.5-1, >1-2, >2-4, and >4 cm, resp.).Results.There were 502 cases with 690 nodules. Overall FNAC sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 95.4%, 98.2%, 99.4%, 86.4%, and 96.0%, respectively. False-negative rates (FNRs) of groups A-E were 3.2%, 5.1%, 1.3%, 13.3%, and 50%, respectively. Accuracy rates of groups A-E were 96.8%, 94.8%, 99%, 94.7%, and 87.5%, respectively.Conclusion.Although accuracy rates of FNAC in thyroid nodules smaller than 0.5 cm are comparable to the other group, thyroid nodules larger than 4 cm with benign cytology carry a higher risk of malignancy, which suggest that those should be considered for intensive follow-up or repeated biopsy.
authors: Department of Surgery, Seoul National University Boramae Medical Center, 20 Boramae-ro 5-gil, Dongjak-gu, Seoul 156-70, Republic of Korea; Department of Surgery, Haeundae Paik Hospital, Inje University College of Medicine, 875 Haeundae-ro, Haeundae-gu, Busan 612-030, Republic of Korea.
authors: Do Hoon
authors: 0000-0002-0029-5772
authors: DH
authors: Koo
authors: Department of Surgery, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: KwangSeop
authors: K
authors: Song
authors: Department of Surgery, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Cancer Research Institute, Seoul National University, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Division of Surgery, Thyroid Center, Seoul National University Cancer Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: Hyungju
authors: 0000-0003-4979-8749
authors: H
authors: Kwon
authors: Department of Surgery, Haeundae Paik Hospital, Inje University College of Medicine, 875 Haeundae-ro, Haeundae-gu, Busan 612-030, Republic of Korea.
authors: Dong Sik
authors: 0000-0003-0617-1161
authors: DS
authors: Bae
authors: Department of Radiology, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: Ji-Hoon
authors: 0000-0002-6349-6950
authors: JH
authors: Kim
authors: Department of Pathology, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: Hye Sook
authors: 0000-0003-0029-5163
authors: HS
authors: Min
authors: Department of Surgery, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Cancer Research Institute, Seoul National University, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Division of Surgery, Thyroid Center, Seoul National University Cancer Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: Kyu Eun
authors: 0000-0002-2354-3599
authors: KE
authors: Lee
authors: Department of Surgery, Seoul National University Hospital, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Cancer Research Institute, Seoul National University, College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea; Division of Surgery, Thyroid Center, Seoul National University Cancer Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Republic of Korea.
authors: Yeo-Kyu
authors: 0000-0003-2349-4624
authors: YK
authors: Youn