Renal cell carcinoma with sarcomatoid features and peritumoral sarcoid-like granulomatous reaction: report of a case and review of the literature.

Granulomatous inflammation with multinucleated giant cells is observed in various infectious and noninfectious diseases. It has been found in association with malignant tumors and designated sarcoid-like reaction. The distinction between a tumor-related granulomatous reaction and a true sarcoidosis can be a problematic issue. A case of renal cell carcinoma with sarcomatoid features (Fuhrman nuclear grade IV) with an extensive peritumoral sarcoid-like reaction and a critical review of the few cases of this association described in the literature have been reported, and the problematic clinical and pathological assessments of such lesions are discussed.