[Complete response of lung metastasis to interferon-alpha therapy after radical nephrectomy for sarcomatoid renal cell carcinoma with Stauffer syndrome: a case report].

A 75-year-old man was admitted to our hospital with liver dysfunction and elevated C-reactive protein level. He was diagnosed with renal tumor by ultrasonography. Computed tomography revealed a renal cell carcinoma (cT3aN0M0) with Stauffer syndrome. Laparoscopic radical nephrectomy was performed. Histological findings indicated clear cell carcinoma with a sarcomatoid component. After 1 month, lung metastasis was detected on an X-ray film. Interferon-α was administered, and complete response was achieved 2 months later. He has shown no evidence of recurrence in 27 months.