Editing Non-RCC Renal Malignancies (section)

== Metastatic tumours ==

* '''Metastatic tumors are the most common malignant neoplasms in the kidney, outnumbering primary renal tumors by a wide margin.''' Autopsy studies have shown that 12% of patients dying of cancer have renal metastases, making the kidney one of the most common sites for metastatic dissemination. The profuse vascularity of the kidney makes it hot spot for the deposition and growth of cancer cells.
* '''The most frequent sources of renal metastases include lung, breast, and gastrointestinal cancers, malignant melanoma, and the hematologic malignant neoplasms'''
* Metastases to the kidney are often multifocal, poorly enhancing, and infiltrative rather than well demarcated, although there are exceptions to these rules.
* Renal metastases should be suspected in any patient with multiple renal lesions and widespread systemic metastases or a history of nonrenal primary cancer. If there is any uncertainty about the diagnosis, percutaneous renal biopsy usually provides pathologic confirmation