Metastasis of oral cancer to the parotid node

The parotid node is an uncommon site of metastasis in head and neck cancer. This study was intended to clarify the incidence and indicators of oral cancer metastases to the parotid node.

We reviewed the records of 253 patients with oral carcinomas who had undergone a total of 289 neck dissections between April 2001 and December 2006. The histologic diagnoses of the primary tumors were squamous cell carcinoma in 239 patients, mucoepidermoid carcinoma in 5, adenoid cystic carcinoma in 4, and miscellaneous others in 5. In all neck dissections, the tail of the parotid gland below the marginal mandibular branch of the facial nerve was resected. The cervical and parotid lymph nodes were isolated from the surgical specimens. One section through the maximum cross-sectional area of each node was examined histologically.

From 183 of the 289 neck specimens, we collected 539 parotid nodes: 222 extraglandular and 317 intraglandular. Of the 253 patients, 10 (4.0%) had 19 parotid node metastases, of which 4 were extraglandular and 15 intraglandular. Parotid node involvement occurred in 2.5% of oral squamous cell carcinoma cases. For the other cancers, there were too few cases to determine a meaningful frequency. In terms of indicators, the likelihood of metastasis to the parotid nodes increased with the number of cancer-positive cervical nodes.

Metastasis to the parotid nodes should be considered in patients with oral cancer. Resection of the tail of the parotid gland is warranted during the neck dissection.