Abstract: Abstract: Objective To analyze the clinical and imaging features of retroperitoneal fibrosis (RPF) secondary to malignant tumors. Methods We retrospectively analyzed 106 patients with retroperitoneal fibrosis from July 1992 to January 2010 in our hospital. Among them 8 cases with malignant tumors were consecutively enrolled in the study. The demographic and clinical data of the 8 patients were collected, and the follow-up was fulfilled regularly. Results We found that there were 5 male and 3 female among the patients, and the mean age was 59.6 years old. The primary neoplasms were from genital system (4 cases), digestive system (2 cases), hematological system (1 case) and malignant neurilemmoma (1 case). One case underwent both the stomach carcinoma and bladder cancer. The clinical symptoms of malignant RPF had no typical features compared to those of the benign RPF. However, the abdominal X-ray computed tomography (CT) exposed some important features which were special to the malignant RPF. If the RPF masses are very extensive, elevate aorta and ureter from spine, or have a lobulated anterior margin, which clue to the malignant diagnosis. In the meanwhile , the abdominal CT can evaluate the management effectiveness and prognosis. Definite diagnosis of the RPF mass depends on the pathology findings. Conclusion Familiarity with the imaging manifestations of retroperitoneal fibrosis is vital to differential diagnosis.

Key words: Retroperitoneal fibrosis, Malignant neoplasms, Computed Tomography, X-ray