RESUMEN
Objective To analyze the clinical and pathological features,diagnosis and differential diagnosis,treatment and prognosis of retroperitoneal angiomyolipoma (RAML).Methods The clinical data of 3 cases diagnosed with RAML,during 2012 to 2014 were studied.The expression of AE1/AE3,Vimentin,HMB45,Melan-A,S-100,SMA,CD10,CD34 and Ki-67 were detected by full automatic immunohistochemistry instrument.Four cases were followed up,the relevant published articles were reviewed as well.Results Four patients contained 3 female and 1 male.Three patients of them were found because of abdominal pain and discomfort symptom,1 case was found on examination.All of them more than 10 cm,and the boundary was not clear.Tumor resection + nephrectomy were used for treatment.Macroscopically,the tumor were consisted of fat,muscle cells and thick walled blood vessels.But they had different proportion.Immunohistochemically:AE1/AE3 negative; Vimentin,HMB45,Melan-A,SMA were positive; S-100 was positive in 3 cases and negative in 1 case; Ki-67 proliferation index were ＜5％.Conclusions The RAML is a rare benign retroperitoneal stromal tumor,which has a complex and diverse pathological organizations.The diagnosis can be made by special immune phenotype in combination with microscopic appearance.