Diffuse bone marrow sarcoid-like reaction associated with renal cell carcinoma.

Sarcoid-like reaction has been documented in association with several types of malignancy, including renal cell carcinoma. We report the case of a 41-year-old man with nonmetastatic renal cell carcinoma and concomitant non-caseating granulomas distributed diffusely throughout the bone marrow. The granulomas resolved after nephrectomy. As far as we know, this is the first reported case of a sarcoid-like reaction primarily involving the bone marrow in association with renal cell carcinoma.