Evaluation of Ultrasonographic Features in Diagnosing Salivary Gland Tumors

Objectives: To evaluate the value of the ultrasonographic features for differentiation between benign and malignant tumors of salivary glands. Methods: Eighty-four cases of salivary gland tumors were analyzed. Sixty-five cases were benign and nineteen were malignant. All cases were confirmed by histopathological examinations. The ultrasonographic features analyzed in this study included the shape of the tumor, the boundary echo, the internal echo and the posterior echo. Each feature was graded into three ranks. For statistical analysis, they were ranked respectively 1, 2, 3. Another 28 cases of salivary gland tumors were analyzed to verify the diagnostic accuracy of the ultrasonography. The Wilcoxon-Mann-Whitney-U-Test, the ROC curve and the Fisher's discriminant test were performed. Results: The differences between benign and malignant tumors were statistically significant in the shape of the tumor (P = 0.001), the boundary echo (P = 0.001) and the posterior echo (P = 0.000). But the difference in the internal echo was not statistically significant (P = 0.195). The diagnostic accuracy was 82.1%, the sensitivity was 63.2%, the specificity was 87.7%. And the predict diagnostic accuracy was 85.7%. Conclusions: This study indicates that the shape of the tumor, the boundary echo and the posterior echo are effective ultrasonographic criteria on differential diagnosis between benign and malignant tumors of salivary glands, but the internal echo is not adequately effective.