Jin Young Kwak MD, Abstract Co-Author: Nothing to Disclose

Eun-Kyung Kim, Abstract Co-Author: Nothing to Disclose

Min Jung Kim MD, Abstract Co-Author: Nothing to Disclose

Eun Ju Son MD, PhD, Abstract Co-Author: Nothing to Disclose

Yu Mee Sohn, Presenter: Nothing to Disclose

To evaluate the diagnostic accuracy of malignant sonographic features of infracentimetric thyroid nodules.

Among 10,005 thyroid lesions that underwent combined ultrasound (US) and US-guided fine needle aspiration biopsy (FNAB), 815 infracentimetric thyroid nodules in 815 patients were evaluated this study. A final diagnosis of benign or malignant nodule was determined using the results of FNAB or postoperative pathologic findings. According to the US findings, we calculated diagnostic performances including sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV). Logistic regression tests were used to evaluate statistical relationships between the US findings and thyroid carcinoma.

The 815 thyroid nodules were divided into 534 suspicious malignant lesions and 281 probably benign nodules, according to US features. Of 534 lesions that showed suspicious US findings, 472 (88.4 %) revealed malignancy upon cytopathology. Two hundred eighty-one showed probably benign US findings and only 23 (8.2 %) lesions revealed malignant results. The odds ratio and area under curve (Az value) were significantly higher in thyroid nodules with microlobulated or irregular margin, marked hypoechogenicity, taller than wide in shape, and microcalcifications. There was a significant difference between the two US groups in the percentage of malignancy (odds ratio=85.4 and Az=0.88), according to logistic regression.

We demonstrated that this system of US classification can efficiently differentiate malignant from benign infracentimetric nodules. Suspicious sonographic features can be useful criteria to identify nodules that should receive FNAB.

Among incidentally discovered infracentimetric thyroid nodules, this study can help the decision about which thyroid nodules should be aspirated.

Kwak, J, Kim, E, Kim, M, Son, E, Sohn, Y, The Significance of Sonographic Characterization for Managing Infracentimetric Thyroid Nodules.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010823.html