Papillary renal cell carcinoma: radiologic-pathologic correlation and spectrum of disease.

Papillary renal cell carcinoma (pRCC) is the second most common type of renal cell carcinoma (RCC). pRCC has unique imaging and clinical features that may allow differentiation from clear cell RCC (cRCC). There have been significant advances in our knowledge of the natural history and treatment of pRCC, with data suggesting that it may be best to manage pRCC differently from the other subtypes of RCC. At contrast material-enhanced computed tomography, pRCC enhances less than does cRCC in all phases of contrast-enhanced imaging. The difference in the degree of enhancement between pRCC and cRCC is due to differences in their intratumoral vascularity. In general, if a heterogeneous mass enhances to a degree similar to that manifested by the renal cortex, it is likely to be a cRCC. A mass that enhances to a lesser degree is likely to be a non-clear cell RCC. It is common for metastatic lesions from pRCC to show enhancement characteristics similar to those of the primary tumor and be hypovascular.