The last decade has brought dramatic changes in our understanding of localized renal tumors. Due to vast improvements in the abdominal imaging modalities of computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI), approximately two-thirds of patients at our center have their renal tumors discovered incidentally. This tumor stage and size migration has vastly improved survival rates; more than 75% of patients with localized renal tumors achieve cure after surgical resection. In addition, the increased presentation of small, incidental tumors has increased the therapeutic options for urologic surgeons with surgical or tumor ablative techniques who now consider preservation of renal function as a goal equally important to local tumor control. Renal cortical tumors, viewed previously as a single type of cancer (ie, hypernephroma, renal cell carcinoma) with a uniform metastatic potential, are far more complex in nature. Renal cortical tumors are a family of neoplasms with distinct histological subtypes and distinct cytogenetic and molecular defects. Metastatic potential, once thought to be dependent only on tumor size, grade, and stage, varies according to tumor histologic subtype, ranging from the most potentially malignant conventional clear cell carcinoma, to the indolent papillary and chromophobe carcinomas, to the virtually benign renal oncocytoma. Surgical approaches to the localized renal cortical tumors now include the classic radical nephrectomy, kidney-sparing surgery, and innovative techniques that involve laparoscopy. New therapeutic modalities, such as renal cryosurgery and radiofrequency ablation, are under active investigation. Whether these new approaches to localized renal tumors will supplement or replace current surgical techniques will depend on the findings of carefully designed and controlled clinical trials.
