Lymph node metastases in adenoid cystic carcinoma of the submaxillary gland

The incidence of neck metastases in adenoid cystic carcinoma of the head and neck is considered low and reported incidence range from 0 to 18%. If tumors of the submaxillary gland are considered separately, the incidence of neck metastases reported ranges from 0 to 100%, with a pooled incidence of 34%, significantly higher (P less than 0.001) than that reported for the parotid gland, which ranges from 0 to 21% with a pooled incidence of 10%. It may be suggested that the high incidence of neck metastases in adenoid cystic carcinoma of the submaxillary gland is due, in some cases, to direct extention of the tumor from the gland to the adjacent nodes or from infiltrated surrounding soft tissues rather than by a classic embolic metastasis. In our series of 10 cases, 4 cases showed lymph node metastases. In 3 of these, slides of the radical neck dissection were available for review and showed direct extension of the tumor from surrounding involved soft tissues, although the possibility of embolic metastasis could not be excluded. In the 3 patients with neck metastases at the time of initial diagnosis, distant metastases also developed early in the course of the disease.