Ultrasonic patterns of parotid masses.

The aim of this study was to define sonographic patterns of expanding parotid lesions. Over a 2-year period, 39 parotid gland masses were examined. Gray-scale sonography with a static scanner using high frequency transducers (5 and 7.5 MHz) provided refined visualization of the normal structure of the gland and the space-occupying mass. There are different sonographic patterns for different types of mass. Lesion malignancy should always be suspected when there is a clearly echogenic mass, especially one with an irregular distribution of the echoes, posterior attenuation, and rough margins (these sonographic features are of no value for lymphomas). All benign lesions have regular margins and are sonolucent at normal gain settings. It is possible to obtain a characteristic sonographic pattern for each specific benign lesion by varying the gain.