Collision Tumor of Urothelial Cell Carcinoma and Clear Cell Renal Cell Carcinoma: A Case Report and Review of the Contemporary Literature.

We present a case of synchronous renal cell carcinoma and urothelial carcinoma. Our case was a true collision tumor and both components were high grade. Metastasis to the adrenal gland by the urothelial carcinoma was observed. The morphologic impression was confirmed with GATA3 expression by the urothelial carcinoma component and PAX8 expression by the renal cell carcinoma component. We have reviewed the contemporary literature of this unusual dual diagnosis.