Ultrasound procedure for the diagnosis of mass lesions in the oral region

Objectives: To examine the diagnostic usefulness and procedures of ultrasonography (US) for mass lesions in the soft tissue of the oral region. Methods: This study involved patients with mass lesions (tumorous lesions and cysts) who had undergone US and histopathological examinations from January 2017 to December 2019. The following points were evaluated by two observers using an evaluation scale: vascularity, echo intensity level, boundary, margin shape, distribution of internal echoes, and capsule. The usefulness of each point for differential diagnosis of tumorous lesions and cysts was statistically analyzed. Results: Forty-five mass lesions in the soft tissue of the oral region (33 tumorous lesions and 12 cysts) were analyzed. There were significant differences in four evaluation points between the tumorous lesions and cysts: vascularity, echo intensity level, boundary, and margin shape. Cysts were almost completely excluded diagnostically, especially when vascularity was observed. There were also significant differences in two evaluation points between nonvascular tumorous lesions and cysts: echo intensity level and boundary. Conclusions: In US examination for mass lesions in the oral region, it was possible to diagnose tumorous lesions and exclude cysts when vascularity was observed. When vascularity was not observed, however, tumorous lesions and cysts could be identified using two evaluation points: echo intensity level and boundary.