Metastatic disease of the parotid gland.

Metastatic lesions of the parotid gland represent the spread of a neoplasm from the primary site to parotid paraglandular, intraglandular, or parenchymal locations. These lesions are frequently difficult to differentiate from primary parotid gland neoplasms. The most common histologic type of neoplasm that metastasizes to the parotid gland is the melanoma. The melanoma is generally found superficial in its metastatic spread. Squamous cell carcinoma is also frequently found, but is usually intraglandular in its metastatic pattern. Although the melanoma and squamous cell carcinoma represent 80 per cent of the metastatic lesions involved in the parotid gland, a variety of other histologic types have been reported. The surgeon must be ready to deal with this complex problem when he enters into an exploratory operation. Even though vigorous treatment is carried out, the histologic types of neoplasms and the anatomic complexities of the area contribute to survival rates between 10 and 15 per cent over a five year period.