The involvement of the parotid gland by tumors other than those of a primary nature has certain curious and practical considerations. This involvement may result from metastasis into the lymph structures of the parenchyma of the gland, metastasis into the paraglandular lymph nodes, and also by direct invasion of the gland from an adjacent tumor. The histopathology covers a wide range of neoplasms with melanoma and squamous cell cancer predominating. The primary sites contributing to parotid gland involvement are predominantly the scalp and ear, but other regions in the head and neck must be considered as potential foci. The significance of this analysis reflects on the application of surgery to the parotid gland for obvious metastatic disease of the gland, for presumptive metastasis to the gland, or as a perimeter of normal tissue about neoplasms that are proximal to the parotid gland.
The character of the lymph system throughout
CONLEY J, ARENA S. Parotid Gland as a Focus of Metastasis. Arch Surg. 1963;87(5):757–764. doi:10.1001/archsurg.1963.01310170043009