Cystadenocarcinoma of the salivary glands with potential lymph node metastasis.

Cystadenocarcinoma derived from the salivary gland in the head and neck region is an extremely rare malignancy. Therefore, the clinicopathological characteristics is not well understood. The purpose of this study was to clarify the clinicopathological characteristics, and present a total of four patients who were treated at the National Cancer Center Hospital East during the period between 1995 and 2012. The patients were all male, with ages ranging from 47 to 74 years old. The primary sites were the parotid glands, submandibular gland and minor salivary gland of the tongue. Within the follow-up period from 19 to 54 months, lymph node metastases were observed in three of the four patients. However, all the patients were salvaged by additional resection, including neck dissection, and remain alive to date without distant metastases. Cystadenocarcinoma is classified as a low-grade histological subtype of salivary gland tumors. Although the tumor has the potential to produce lymph node metastases, as shown in our patients, it is generally an indolent tumor with a good prognosis as compared with high-grade subtypes. This study suggests that a long-term follow up paying close attention to lymph node metastases is necessary for cystadenocarcinoma.