Ultrasonography of cervical lymph node metastasis in patient with oral squamous cell carcinoma: Characteristics of extracapsular lymph node invasion

The purpose of this study was to evaluate ultrasonographic findings of extracapsular invasion. Ultrasonography of 61 metastatic lymph nodes (37 patients) from oral squamous cell carcinoma performed between 1987 and 1997 were compared with pathological findings retrospectively. Capsule of the stage IV lymph nodes, which were histologically confirmed to have extra capsular invasion, was thin, while that of stage III lymph nodes, which predominantly had a metastatic lesion, was thick. Stage IV lymph nodes tended to have irregular margin and stage III lymph nodes tended to have enhancement of bottom echo or appearance of halo on ultrasonographs. These results suggested that enhancement of bottom echo and appearance of halo on ultrasonographs indicate a thick capsule of metastatic lymph nodes, and that the presence of irregular margin indicate the wide extra capsular invasion of the metastatic lymph nodes.