Malignant Epithelial Tumors of the Parotid Gland

Abstract

Cancer of the parotid gland represents about 20% of all parotid tumors. It either occurs “de-novo” or “on top of pleomorphic adenoma.” There is no sex predilection, and the age of developing this cancer is usually above 50 years. Malignant tumors are as varied as their benign counterparts. Certain tumors are “low-grade” (polymorphous low-grade adenocarcinoma, acinic cell carcinoma, epithelial-myoepithelial carcinoma), while others are “high-grade” (salivary duct carcinoma, large cell carcinoma, and small cell carcinoma). The first echelon lymph node (LN) of metastases is the intra- and peri-glandular nodes. The next echelon is level II LNs. Hematogenous spread occurs very late and is mainly to the lungs and bones. However, adenoid cystic carcinoma tends to grow through peri-neural lymphatics with increased risk of nerve involvement, intra-cranial extension, and increased rate of recurrence. In this chapter, characteristic features and management of the individual types of malignant parotid tumors will be discussed.