[Value of invasive preoperative imaging in kidney tumors of malignant or uncertain character].

Preoperative staging of malignant renal tumors or undetermined dignity is mainly performed noninvasively using CT or MRI. In cases with vascular invasion or a solitary kidney extensive invasive evaluation of the tumor can influence preoperative planning. We report two cases of oncocytoma and renal cell carcinoma with extensive imaging using DSA or helical CT-cavography.