Abstract
Lymph node metastasis of twenty-two patients with carcinoma of the upper gingiva and/or hard palate were retrospectively analyzed using the CT images obtained by the initial and follow-up studies. Cervical metastasis developed in 10 of 22 cases : in 3 cases initially and in 7 after treatment. Metastasis to the contralateral nodes was observed in 8 cases : 1 case bilaterally in the initial study, 3 bilaterally in the follow-up studies, 3 contralaterally after neck dissection of the initially involved side, and 1 contralaterally in the follow-up study. Contralateral lymph node metastasis may be caused by the lymphatics in the area of the upper gingiva and hard palate running to the other side. Metastases to the lateral retropharyngeal node was observed in 3 cases. Two of them were observed in the cases with cervical node involvement previously or simultaneously, and one in the case of recurrent tumor of the upper gingiva. All three had undergone surgical procedures before metastasis occurred. Metastasis to the lateral retropharyngeal node may be caused by the lymphatics, via the soft palate, through the incisive canal from the anterior upper gingiva and the lymphatics from the palatal surface of the upper gingiva, and the retrograde lymphatic flow in the efferent vessels induced by the residual tumor in the upper neck region and/or neck dissection.
