Abstract
To clarify whether primary tumor shape and thickness of T1 and T2 tongue carcinoma, evaluated by intraoral sonography, provides information about subsequent lymph node metastasis, 28 consecutive patients were included in this retrospective study. The shape and thickness of primary tumors were evaluated with a 7.5 MHz convex intraoral transducer. Of the 28 patients, 14 underwent neck dissections, and 10 were proved to have histopathologically metastatic nodes. Primary tumors were divided into two categories according to shape: nodular or wedge-shaped. The wedge-shaped tumors showed a significantly high incidence of subsequent lymph node metastasis. Tumor thickness was measured vertically from the surface to the bottom of the tumor. Using 1.0cm as a cut-off thickness, the accuracy for predicting subsequent lymph node metastasis was 71%. If the rule that patients with wedge-shaped primary tumors had metastatic nodes was applied, the accuracy for predicting subsequent lymph node metastasis was 79%. In conclusion, the shape of primary tumor, evaluated by intraoral sonography, was useful to predict occult lymph node metastasis in patients with T1 and T2 tongue carcinoma.
