Ultrasonographic evaluation of thyroid nodules: comparison of ultrasonographic, cytological, and histopathological findings
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Thyroid ultrasonography (US) and fine needle aspiration biopsy (FNAB) are the most important tools in evaluating thyroid nodules. A total of 3,404 nodules in 2,082 cases referred to our clinic between 2005 and 2008 were analyzed retrospectively. Considering US features of nodules, risk factors predicting malignancy were: margin irregularity as the most important predictor, hypoechoic pattern and microcalcification (Odds ratios: 63.2, 13.3, 7.03, respectively). Cytologic results of the patients were as follows: 1,718 (82.5%) benign, 196 (9.4%) suspicious, 68 (3.3%) nondiagnostic, and 100 (4.8%) malignant. In histopathologic examination, we determined a malignancy rate of 7.59% (158/2082). We calculated the sensitivity of FNAB as 89.16%, specificity as 98.77%, positive predictive value as 96.10%, negative predictive value as 96.39%, and accuracy as 96.32%. In cytologic examination, the malignancy rate of subcentimetric (≤1 cm) nodules was higher than supracentimetric (>1 cm) nodules (5.1% vs. 1.5%, P = 0.001). In postoperative histopathologic examination, although the malignancy rate of subcentimetric nodules was higher than that of supracentimetric nodules, the difference was statistically insignificant (5.5%, 4.4%, respectively; P > 0.05). Cytologically diagnosed malignancy was detected in 4.5% of patients with multiple nodules, while it was present in 6% of patients with solitary nodule indicating no significant difference. However, postoperative histopathologic examination revealed a significantly higher malignancy rate in patients with solitary nodule compared to in patients with multiple nodules (11.7%, 6.5%; respectively, P < 0.001). The malignancy rate of patients operated for suspicious cytology was found to be 46.15%; for nondiagnostic cytology, it was 64.29%. In conclusion, ultrasonographically, hypoechoic pattern, microcalcification and margin irregularity of thyroid nodules are important features in determining the malignancy risk. The nodule size alone still remains inadequate to exclude malignancy risk.
KeywordsUltrasonography Fine needle aspiration biopsy Cytology Histopathology
- 3.M.C. Frates, C.B. Benson, J.W. Charboneau, E.S. Cibas, O.H. Clark, B.G. Coleman, J.J. Cronan, P.M. Doubilet, D.B. Evans, J.R. Goellner, I.D. Hay, B.S. Hertzberg, C.M. Intenzo, R.B. Jeffrey, J.E. Langer, P.R. Larsen, S.J. Mandel, W.D. Middleton, C.C. Reading, S.I. Sherman, F.N. Tessler, Ultrasound Q. 22, 231–238 (2006)CrossRefPubMedGoogle Scholar
- 7.H. Shimura, K. Haraguchi, Y. Hiejima, N. Fukunari, Y. Fujimoto, M. Katagiri, N. Koyanagi, T. Kurita, M. Miyakawa, Y. Miyamoto, N. Suzuki, S. Suzuki, M. Kanbe, Y. Kato, T. Murakami, E. Tohno, H. Tsunoda-Shimizu, K. Yamada, E. Ueno, K. Kobayashi, T. Kobayashi, T. Yokozawa, M. Kitaoka, Thyroid 15, 251–258 (2005)CrossRefPubMedGoogle Scholar
- 16.E.K. Kim, C.S. Park, W.Y. Chung, K.K. Oh, D.I. Kim, J.T. Lee, H.S. Yoo, Am. J. Roentgenol. 178, 687–691 (2002)Google Scholar
- 32.J. Rosai, M.L. Caracangiu, R.A. DeLellis, in Atlas of Tumor Pathology: Tumors of the Thyroid Gland, ed. by J. Rosai (Armed Forces Institute of Pathology, Washington, DC, 1992)Google Scholar