Parotid Gland Metastasis from Renal Carcinoma

The salivary gland most frequently involved with secondary cancer is the parotid gland. Metastases are responsible for 21-42% of malignant parotid tumors. Malignant melanoma and squamous cell cancer are the two most common tumors to metastasize to the parotid gland. Metastatic adenocarcinoma to this site has rarely been reported. Secondary renal cell carcinoma has been reported in many structures, including the brain, sinonasal tract, lungs, abdomen, genitourinary tract, bone, soft tissue, and lymphatics. Histologically proven parotid metastasis has been previously reported in only one patient. Two patients have recently been diagnosed and treated at our institution for this rare disease. The clinical presentation of each patient was quite different. One patient presented with parotid and pulmonary metastases seven years after resection of a renal tumor. Another patient had resection of a parotid mass revealing an occult metastasis from a renal cell carcinoma. Further evaluation revealed a locally extensive asymptomatic hypernephroma. The survival from the time of discovery of the parotid metastasis was 46 months for the former patient, while the latter patient is alive after 20 months. Differentiation of these tumors from vascular disorders (aneurysm or arteriovenous fistula) required selective angiography and computed tomography. Surgical excision via superficial parotidectomy with facial nerve preservation is necessary for palliation, particularly to avoid massive hemorrhage which may occur upon tumor extension into the oropharynx.