ObjectiveTo retrospectively analyze the clinical data of 16 patients with renal cell carcinoma complicated with sarcomatoid differentiation, so as to discuss the treatment and prognosis of the condition. MethodsA total of 547 patients with renal cell carcinoma were admitted in our department during 2005-2009, and 16(2.9%) of them also had sarcomatoid differentiation, including 7 males and 9 females, aged (52 ± 10) years old, ranging 36-70 years old. Gross hematuria was found in 5 patients, backache in 5, fatigue and weight loss in 2, cough and hemoptysis in 1; and 3 patients were accidentally found with renal occupation during physical examination. All tumors were solitary, with 7 in the left and 9 in right. The maximum tumor diameter was (7.8±4.1) cm, ranging 2-15 cm. Full examination was done to confirm the tumor stage preoperatively. Preoperative examination showed that 2 patients had retroperitoneal lymph node enlargement,1 had right pulmonary hila lymphatic metastasis, 1 had liver metastasis, 2 had renal vein and (or) the inferior vena cava tumor thrombi, 3 had bone metastases, 1 had invasion of ipsilateral adrenal gland, and 1 had invasion of the upper ureter. All the 16 patients underwent surgical treatment,and their specimens were subjected to H-E staining and immunohistochemical examination. Five patients were treated with INF-α after operation and were followed up. ResultsAll patients received radical nephrectomy. Pathological examination showed that 9 patients had clear cell renal cell carcinoma with sarcomatoid differentiation, 3 had chromophobe renal cell carcinoma with sarcomatoid differentiation, and the other 4 had unclassified renal cell carcinoma with sarcomatoid differentiation. No recurrence or metastasis was seen in the 4 pT1N0M0 patients. All the pT2-T4 patients died, with the progression-free survival time being (5.6±4.5) months, ranging 2-16 months; the overall survival time was (8.3±5.6) months, ranging 3-20 months. ConclusionPreoperation staging of patients with renal cell carcinoma complicated with sarcomatoid differentiation has a great impact on patient survival. Operation is the most effective treatment for patients with early stage, and routine follow-up examination is recommended postoperatively.Targeted therapy may be an effective way for patients of advanced stage.