Renal cell carcinoma metastasizing to salivary glands: Systematic review

Distant metastasis to salivary glands is a very rare event. Renal cell carcinoma (RCC) has been known for its high propensity of metastasis to unusual locations and salivary glands are one among those sites. Approximately 0.1% of all salivary gland metastatic neoplasms originate from renal malignancies Literature has reported several studies analysing the metastatic tumors to the oral region. However, very little research work has been published to date to analyse solely the RCC metastasizing to the salivary glands. Thus, this review was conducted to examine the published cases of RCC metastasizing to salivary glands in the literature to date and to learn about their characteristics. An electronic search of the published literature was performed without publication year limitation in PubMed/ Medline, Scopus, Google Scholar, Web of Science, Science Direct, Embase, and Research Gate databases, using mesh keywords like ('Renal cancer', OR 'Renal carcinoma' OR 'Renal cell cancer' OR 'Renal cell carcinoma'), AND ('Metastasis' OR 'Metastases'), And ('Salivary glands' OR 'Parotid gland' OR 'Submandibular gland' OR 'Sublingual gland'). We also searched all related journals manually. The reference list of all articles was also checked. Our research revealed a total of 83 relevant papers (1965-2022) with 100 patients. Parotid was the most predominant gland affected. 8% of patients died with a mean survival time of 1.3 yr. From this research, it can be concluded that RCC metastasizing to salivary glands is a rare occurrence. Careful evaluation of these cases is needed in order to raise awareness of these lesions and gain a better understanding of their characteristics for clinical as well as global implications.