Comparative studies on fine-needle aspiration cytology with ultrasound scanning in the assessment of thyroid nodule.

The clinical usefulness of ultrasound scanning in the assessment of thyroid nodule was examined. The total diagnostic accuracy for aspiration biopsy cytology (ABC) in the differentiation of benign from malignant thyroid nodules was 92.4% in 26 patients, which is similar to that of previous reports when compared with the findings of pathological examination by surgery. Additionally, the diagnostic efficacy of high resolution ultrasonography was evaluated based on the results of ABC. When the echogram of 90 patients with a thyroid nodule was divided into eight patterns according to Obara's classification, only 64.3% of the carcinoma exhibited the typical malignant pattern of ultrasonography and 21.4% of the carcinoma exhibited the ultrasonographically homogenous nodule with a clear margin, which was often observed in the benign nodules. Therefore, it is necessary to be very careful when differentiating malignant from benign thyroid nodules by ultrasonography. In conclusion, although high resolution ultrasonography provides useful information for the assessment of most thyroid nodules, all ultrasonography (including high resolution ultrasonography) should be combined with ABC for the final diagnosis.