[Evaluation of real-time sonography in the pretherapeutic staging of malignant tumors of the tongue and mouth floor].

Based on our three years experience with about 200 transcutaneous real-time sonographies of the tongue and the floor of mouth, an assessment of the determination of size and site of 38 pretherapeutically examined malignant tumours (35 squamous cell carcinomas) was made. The patients were examined in reclined position, the head retroflected. Curved array transducers of 5 or 7.5 MHz and a silicon elastomer block as interface turned out to be optimal. All tumours could be detected by sonography as hypoechoic, more or less homogeneous, ill-defined areas. Two thirds of the tumour ulcerations could be seen as hard hyperechoic reflexes within the hypoechoic areas. When comparing the maximal diameter of tumours of the 20 operated patients, we found an agreement (5 mm tolerance) of sonography with the surgical specimen in 14 of 20 tumours (70%), of sonography with the clinically estimated diameter in 10 of 20 tumours (50%), whereas the clinically estimated diameter was in agreement with the surgical specimen in only 8 of 20 tumours (40%). A peritumoral inflammatory infiltration can simulate a larger tumour size in sonography. The extent of tumours within the tongue, to the floor of mouth, the lateral pharyngeal wall and the preepiglottic space was documented correctly in most cases. In three cases a previously unknown spread across the midline was found sonographically. Including the sonographic findings in the TNM classification, 5 T1 tumours would have been staged as T2 and one T3 tumour as T4. Inflammatory diseases of the tongue can show the same sonomorphology as malignant tumours.