[Thyroid nodules; evaluation of malignancy by ultrasonography]

Preoperative ultrasonic examination was correlated to final pathological diagnosis in 102 cases which underwent thyroidectomy in our clinic from 1979 to May 1985. Preoperative ultrasonic diagnosis was as follows: Sensitivity was 78% (45/58 cases), and specificity was 86% (38/44 cases). Four factors in ultrasonic image were considered: Shape, boundary, internal echo and margin were featured, and correlated to malignancy in 75 cases with mainly solid nodules. Among 34 nodules with irregular shape, 33 (97%) were pathologically malignant and 40 of 42 (95%) with rugged boundary were also malignant. Whether internal echo was even or not could not be used as a diagnostic criteria. Similarly, whether a nodule had well defined margin or not was found not to be a significant criteria in order to differentiate malignant from benign lesions. In 15 of 34 cases with lymph node metastases, metastatic lymph nodes were detected by ultrasonography. Lymph node metastases must be also evaluated by ultrasonography preoperatively in thyroid diseases. Each of these factors must be considered individually in the diagnosis of thyroid nodules. By evaluation of the ultrasonography findings the pathological characteristics may be inferred, and consequently being possible to reach a correct diagnosis.