Wegener granulomatosis presenting as renal mass.

Wegener granulomatosis involves both the respiratory and genitourinary systems. Kidney lesions are invariably focal. Wegener granulomatosis only rarely affects other genitourinary organs and, until now, has not been described as a mass in the kidney. In the case presented, the diagnosis was unknown before surgery, though clinically suspected. The management, which included nephrectomy and chemotherapy with cyclophosphamide (Cytoxan) and prednisone, caused a marked improvement, and the patient was discharged in stable condition.