Case Report Metastasis of renal cell carcinoma to hemangioblastoma of the spinal cord in von Hippel-Lindau disease: report of a case and review of literature

Tumor-to-tumor metastasis is considered to be an unusual event. Here, we describe a patient with von Hippel-Lindau (VHL) syndrome with metastasis of renal cell carcinoma (RCC) to a hemangioblastoma (HAB) of the spinal cord. Histological examination revealed cells with clear cytoplasm arranged in alveolar or tubular patterns in most fields of view. In the other area, the tumor showed abundant thin-walled vessels and clear cells. Immunohistochemically, the tumor cells were positive for vimentin and CK-8/18, which indicated a metastatic lesion of RCC clear cells. The diagnosis of RCC metastasis within an HAB might be overlooked because they have similar morphological characteristics. Detailed histological analyses and immunohistochemical stains should be helpful to determine whether HAB contain metastatic RCC, especially in patients with VHL syndrome.