- Patients must have at least one site of disease which in the opinion of the investigator is safely accessible by CT guided biopsy or metastasectomy. Safely accessible metastatic disease will be defined to include those lesions which are palpable with no overlying viscera and are at least 2cm in size. Given the paucity of subcutaneous lesions in RCC, lesions which are felt to be safe to biopsy will also be allowed. These lesions include pleural-based tumors, peripheral liver lesions, kidney lesions and bone lesions with exophytic soft tissue component. As with palpable lesions, these other lesions should be at least 2cm in size with no overlying viscera.