The ultrasound examination in assessment of parotid gland tumours: the novel graphic diagram.

Ultrasound is one of the main diagnostic techniques for parotid gland tumours. It is inexpensive, non-invasive and widely available. However, interpretation of the images is highly subjective and constitutes a major limitation. To overcome this problem, we developed a graphic diagram to provide a standardised template that can be used for more precise identification of the tumour localisation within the parenchyma of the parotid gland. This new diagram may be used to provide surgeons with an improved and more objective localisation of the tumour. The study included 237 patients who underwent surgery for parotid tumours. To obtain the precise spatial location of the tumours, three topographic coordinates of tumour location in the coronal, sagittal and transversal plane were marked preoperatively during sonography within the parenchyma of the parotid gland. The localisation identified ultrasonically was then compared to the postsurgical report: 197 (83 %) tumours were found within the superficial lobe of the parotid gland and 40 (17 %) within the deep lobe of the parotid gland. In 157 (66 %) cases, tumours were found within the lower pole of the parotid gland, and in 64 (27 %) at the level of earlobe and its insertion, 16 (7 %) tumours were located at the level of the tragus and above it. Based on the results obtained, a graphic diagram of parotid gland tumour locations was developed.