Although the diagnostic accuracy of thyroid cancer by fine needle aspiration cytology (FNAC) is increasing, there are some nodules for which ultrasonography and FNAC show indeterminant. The purpose of this study was to determine the usefulness of thyroid ultrasonography by the surgeon prior to operation

Forty-nine patients who underwent thyroid operations between June 2006 and January 2007 were selected for this study. Thyroid ultrasonography was performed on each patient.And we recorded and analyzed the shape and the margin of the nodule, internal echogeneiety, heterogeneiety, the presence of microcalcification, height versus width, and the presence of level VI lymph node larger than 3 mm, assigning each a score of 1, 2 or 3.

The average score was 17.1. Assuming an average score over 14 is considered to be malignant, the sensitivity, specificity, positive predictive value, and negative predictive value were 95.6%, 88.9%, 91.7%, 94.1% respectively. Statistically significant characteristics of malignancy were the shape and the margin of the nodule, internal echogeneiety, microcalcification, taller than wide shape and the presence of enlarged VI lymph nodes. The heterogeneiety had no significant P value.

When malignancy cannot be confirmed even after repeated FNAC, preoperative ultrasonograpy performed by surgeons can be a reliable test and helpful for operations.