Katy Martin, Lisette Martin, Cristina Frezzini, Ali Khurram, Muzzamil Nusrath
Renal cell carcinomas (RCC) are malignancies that can present as distant metastases at the time of diagnosis. Parotid malignancies can often be the first clinical indicator of metastatic disease, even years after curative surgical treatment. Only around 100 cases of metastatic RCC in the parotid gland have been reported in literature, and even less commonly with solitary metastasis to the parotid after five years.
We present a case of a 56 old male who was referred to the Oral and Maxillofacial team complaining of a slow growing left parotid mass. The patient had a background history of renal cell carcinoma which had been managed surgically with left nephrectomy seven years previously. His urology follow-up had been unremarkable.
Clinical examination revealed a mass within the superficial lobe of the parotid gland, with no associated facial nerve weakness. A core biopsy histologically confirmed a metastatic deposit of clear cell renal cell carcinoma. Preoperative imaging confirmed no evidence of regional disease. A left partial superficial parotidectomy was performed and histological examination confirmed the presence of a highly vascular RCC. Immunohistochemistry confirmed strong membranous positivity for CD10 and focal positivity for renal cell carcinoma. Postoperative recovery was unremarkable.
Whilst the parotid gland is often a location for metastases of multiple malignancies, solitary RCC deposits within the parotid gland are extremely rare. Histopathology and immunochemistry are invaluable tools in managing parotid cell tumours in aiding the clinician decipher the metastatic process and primary tumour location. These patients are best treated in a multidisciplinary setting. In this case, the metastatic deposit was solitary within the superficial lobe of the parotid gland. In cases with multiple deposits, a total parotidectomy with selective neck dissection should be considered.