epistaxis as the first manifestation of silent renal cell carcinoma: a case report with relevant literature review

the paranasal sinuses are known to be a rare location for metastasis. renal cell carcinoma (rcc) is the most frequent primary tumor to metastasize to the sinonasal region, followed by lung and breast cancer. in particular, clear cell type rcc, which represents approximately 85% of rccs, is characterized by early metastasis, and it sometimes spreads to unusual sites (1, 2). metastatic tumors in the paranasal sinuses are distributed in the maxillary, sphenoid, ethmoid, and frontal sinuses, in order of decreasing frequency. symptoms are usually nonspecific, but epistaxis is the most common sign, due to the hypervascularity of the primary tumor. the prognosis is uncertain, but the 5-year survival rate fluctuates between 15% and 30%. the purpose of this case report is to document a rare case of silent rcc that first presented as epistaxis due to nasal cavity and ethmoid sinus metastasis.