Sarcomatoid renal cell carcinoma: basic biology, clinical behavior and response to therapy

All histological subtypes of renal cell carcinoma (RCC) are capable of undergoing sarcomatous transformations that result in tumors with distinctive appearances and aggressive biologic behavior. The history of sarcomatoid renal cell carcinoma (SRCC) is traced from the time when it was thought to be a true sarcoma to the present when its epithelial origin is fully appreciated. The distinctive macroscopic and microscopic features as well as various diagnostic methods are reviewed. A description of the complex genetic aberrations associated with various types of RCC are summarized. It is apparent that the chromosomal changes known at this time are common to both SRCC and classic RCC while the unique alterations that lead to the sarcomatoid transformation remain unknown. The mode of presentation, the clinical behavior, and the prognostic factors common to SRCC are also reviewed. Finally, the various modalities that have been examined for the treatment of SRCC are detailed to evaluate for patient response and overall improvement in survival. A comparison of the treatment methods suggest that high-dose recombinant interleukin-2 may hold the greatest promise in improving the dismal prognosis associated with this disease. (C) 2001 Elsevier Science Inc. All rights reserved.