CT and MRI Findings of the Retroperitoneal Schwannoma

Objective:To study the CT and MRI findings of the retroperitoneal schwannoma,and differ the benign to malignant tumor.Methods:Thirteen cases of retroperitoneal schwnnoma proved by pathology were presented.There were ten male and three female,with an average age of 45.0 years old.Among those cases,four cases were benign tumors,and nine cases were malignant tumors.CT studies were obtained in eleven cases in which CT enhancement studies were done in four cases,MR studies in four cases.Results:Tumors were located in the lateral retroperitoneal space or in the lateral pelvic space.Heterogeneous density or signal intensity was presented in 12/13 cases.Cystis changes were showed in 9/13 cases.There was no any lymphatic adenopathy.For the benign lesion,small with well-demarcated round shape were demonstrated.But in malignant tumor,a big mass with irregular or nodular shape was found.Calcification was seen in 3/9 cases.Irregular enhancement was presented in 4/4 cases.Invasive characteristics were showed in 7/9 cases.Metastasis were in 4/13 cases.Conclusion:If a tumor occurs in the lateral retroperitoneal space,with cystic change,the diagnosis of retroperitoneal schwnnoma should be considered.CT and MRI can differ benign to malignant tumor. [