Tumor-to-tumor metastasis: report of an autopsy case of lung adenocarcinoma metastasizing to renal cell carcinoma.

: Metastasis of one tumor to another tumor within the same individual is considered rare. Lung cancer metastatic to renal cell carcinoma represents the most common combination of such tumor-to-tumor metastases. We present the autopsy case of a 97-year-old woman with metastatic adenocarcinoma of the lung to renal cell carcinoma.