Renal cell carcinoma metastatic to the nasal cavity.

Metastatic renal cell carcinoma of the nasal cavity is very rare. A 76-year-old man presented with epistaxis and admitted to our hospital. His past histories were right radical nephrectomy for renal cell carcinomas at the age of 68 years and brain infarction at the age of 75 years. Laryngoscopic examination revealed a red polyp of the right nasal cavity. Imaging modalities including CT and MRI also revealed a tumor measuring 2 x 3 x 2 cm. Angiography showed that the tumor is very hypervascular. Clinical diagnosis was angiogenic tumors including hemangioma, sinonasal hemangiopericytoma, and paraganglioma. A blood data showed anemia and low platerets, and bone marrow biopsy revealed myelodysplastic syndrome. A coiling embolization of the feeding artery was performed, and the tumor reduced markedly. The tumor was resected almost entirely. Pathologically, the tumor was 2 x 1.5 x 1.5 cm red tumor. The tumor cells had clear cytoplasm, and arranged in a trabecular pattern lined by a layer of endothelial cells. Atypia is mild. Immunohistochemically, the tumor cells were positive for pancytokeratin (AE1/3, CAM5.2), RCC ma, CD10, and Ki-67 (labeling=20%), but negative for CD34, factor-VIII-related antigen, CEA, EMA, melanosome (HMB45), S100 protein, p53, and HepPar-1. The pathological diagnosis was made without knowledge of kidney status. A pathological diagnosis of metastatic renal cell carcinoma of clear cell type (grade 1) was made. The patient is now free from tumor, and palliative chemoradiation is considered.