Metastasis to the submandibular gland in head and neck carcinomas.

BACKGROUND The purpose of this retrospective chart review was to determine whether and how the submandibular gland is involved in metastases of squamous cell carcinoma of the head and neck. METHODS We reviewed the records of all patients for whom pathology specimens were available after neck dissection for primary head and neck cancers at two institutions. RESULTS One hundred sixty-nine patients were included in the study, 27 underwent bilateral neck dissections, and 196 submandibular glands were resected and sent for pathology. One hundred forty-four glands had normal histologic findings. Normal or benign histologic changes were present in 187 glands. Three submandibular glands showed invasion from a locally involved lymph node, and six had direct extension from a primary lesion. The primary lesions were all ipsilateral to the involved gland and originated from cancers of the floor of the mouth, alveolar ridge, and tongue. No submandibular glands showed pathologic evidence of metastases. CONCLUSIONS Because the submandibular gland has no intraparenchymal lymph nodes, its involvement in upper aerodigestive tract carcinomas must be through extension from a locally involved lymph node or the primary tumor. Previous work has demonstrated that the submandibular gland can undergo transplantation out of the neck with subsequent reimplantation, as a possible means of protection from the effects of radiation. We demonstrated the submandibular gland to be involved only in cases of ipsilateral oral cavity tumors or metastasis to ipsilateral level I lymph nodes. We conclude that it is oncologically sound to consider transplantation and replantation of the contralateral submandibular gland for patients with head and neck squamous cell carcinoma when level I lymph nodes are unlikely to be involved.