Pathology, biology, and clinical staging of renal cell carcinoma.

The clinical features of renal cell carcinoma may include complex systemic presenting symptoms unrelated to the urogenital tract. A particular characteristic of the tumor is the presence of widespread and unusual metastatic sites due to the high frequency of extension of the tumor into the renal vein and to subsequent hematogenous invasion. The prognosis, in general, is poor. A contributing factor is that the silent nature of the primary tumor frequently results in far-advanced disease at the time of diagnosis. The overall 10-year survival rate after nephrectomy for renal cell carcinoma is 18% to 27%. The evidence that an immune mechanism regulates tumor growth is minimal. Paraneoplastic syndromes and ectopic hormone production result in multiple-systematic symptoms and abnormal clinical chemistries. Compared with other methods of staging, the new TNM system contains a greater number of separate categories for different levels of renal vein, vena caval, and lymph node metastases. Although the system is complicated, it allows for a more accurate determination of prognosis. Computerized tomography appears to be the most effective and accurate method for making staging determinations.