Collecting duct carcinoma producing granulocyte-colony-stimulating factor (G-CSF).

We present a 67-year-old male with a rare case of collecting duct carcinoma producing granulocyte colony-stimulating factor. He was referred to us with lumbago and fever. Laboratory testing showed leukocytosis and computed tomography revealed a left renal mass. After chemotherapy with gemcitabine and nedaplatin, computed tomography showed a partial response. A left nephroureterectomy was performed. The histopathological diagnosis was collecting duct carcinoma producing granulocyte-colony-stimulating factor. White blood cell levels were reduced to 9900/mm(3). No recurrence was detected after completion of adjuvant chemotherapy and the patient was discharged from the hospital. However, 3 months later, computed tomography revealed multiple lung metastasis. Nedaplatin- based chemotherapy was administered but computed tomography after chemotherapy identified a progressive disease. The patient died 9 months after the operation.