To assess the depth of tumor invasion, we performed ultrasonography (US) in patients with T1 and T2 carcinomas of the tongue, using a 7.5 MHz intraoral electronic sector scanner (SSD-650; ALOKA, Tokyo, Japan). The ultrasonographic findings were compared with pathologic findings. The study cohort consisted of 21 patients with squamous cell carcinoma of the tongue who were admitted to our institution from April 1993 through October 1996. Pathologic findings of primary lesions obtained by resection, were studied. The results were as follows.
1) US detected all lesions, irrespective of the depth of carcinoma invasion.
2) The mean depth of T1 carcinoma invasion on pathological examination was 3.6mm, and that of T2 was 8.4mm. The mean error in the depth of T1 carcinoma invasion between US and pathologic findings was 0.4mm and that between T2 and pathological findings was 0.8mm.
Our results suggest that US with an intraoral scanner is useful for detecting early tongue cancer and should be used routinely in clinical practice.
