Alpha-fetoprotein-producing renal cell carcinoma

Alpha-fetoprotein (AFP) is recognized as a tumor marker of yolk sac tumors, liver cancer and some other cancers of the digestive organs. Renal cell carcinoma (RCC) producing AFP is a rare entity. A case of AFP-producing RCC with solitary bone metastasis, but without liver involvement, is reported. The stain specific to AFP proved the presence of AFP in the cytoplasms of more cells of the renal tumors. Additionally, the other published cases are reviewed. These cases indicate that mesoderm-originating malignant tumors such as RCCs can produce AFP in some situations. So, AFP is probably more universal than believed, although it is generally a popular and useful tumor marker for hepatocellular carcinomas and yolk sac tumors.