Objective: to evaluate the value of the ultrasonographic features for differentiation between benign and malignant tumours of salivary glands.
Methods: eighty-four cases of salivary gland tumours were analysed. Sixty-five cases were benign and 19 were malignant. All cases were confirmed by histopathological examination. The ultrasonographic features analysed included the shape of the tumour, 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 and 3. Another 28 cases of salivary gland tumours were analysed to verify the diagnostic accuracy of the ultrasonography. All data were analysed using SPSS 16.0 for windows. The Mann-Whitney U test, the receiver operating characteristic (ROC) curve and Fisher's discriminant test were performed.
Results: The differences between benign and malignant tumours were statistically significant in the shape of the tumour (P = 0.001), the boundary echo (P = 0.001) and the posterior echo (P = 0.000). However, the difference in the internal echo was not statistically significant (P > 0.05). The diagnostic accuracy, sensitivity and specificity were 82.1%, 63.2% and 87.7%, respectively, while the predicting diagnostic accuracy was 85.7%.
Conclusion: the present study indicates that the shape of the tumour, the boundary echo and the posterior echo could be effective ultrasonographic criteria for differential diagnosis of benign tumours from malignant tumours in the salivary glands.