Subtypes of renal cell carcinoma. Different onset and sites of metastatic disease.

Different subtypes of renal cell carcinoma have different genetic features and prognoses. Whether the patterns of metastatic spread of different subtypes of renal cell carcinoma are different is unknown. To assess this, we reviewed the time course and sites of all pathologically confirmed metastatic disease in patients who underwent resection of the primary tumor at Brigham and Women's Hospital, Boston, MA, between 1973 and 1997. In 82 patients, 119 metastatic lesions were identified. Compared with clear cell tumors, papillary tumors were more likely to be Fuhrman grade 3 or 4, to have metastases present at the time of resection, and to involve lymph nodes but not lung. Metastases associated with chromophobe tumors developed in 3 patients, all of whom had Fuhrman grade 2 tumors, and were found only in the liver. We conclude that different subtypes of renal cell carcinoma develop pathologically confirmed metastases at different times and sites. The value of Fuhrman grading may depend on the subtype of renal cell carcinoma.