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.

Objective To investigate the efficacy of leflunomide combined with prednisone in the induction therapy of proliferative lupus nephritis (LN).Methods A prospective,multicenter,randomized controlled clinical trial was conducted in patients with biopsy-proved proliferative lupus nephritis recruited from 15 renal centers from 2013 to 2015.Patients were randomized to two groups.Oral leflunomide or intravenous cyclophosphamide was given to patients in each group.Both groups received a tapering course of oral prednisone therapy.All patients were followed up for 24 weeks.The blood biochemistry,urine index,clinical curative effect and adverse reaction were recorded and analyzed statistically.Results A total of 100 patients were enrolled in this clinical trial,including 48 patients in leflunomide group and 52 patients in cyclophosphamide group.After 24 weeks,the overall response rate was 79％ (95％ CI 67％-90％) in the leflunomide group and 69％ (95％ CI 56％-82％) in the cyclophosphamide group.23％ (95％CI 11％-35％) of patients in leflunomide group showed complete remission compared with 27％ (95％CI 24％-30％) in cyclophosphamide group (P=0.35).The levels of 24-hr urine protein excretion,SLEDAI and anti-dsDNA antibody titers were decreased in patients treated with leflunomide group after 24-weeks treatment.And the levels of serum albumin and complement 3 after treatment were significantly higher compared with these before treatment.There was also no significant difference in changes of 24-hr urine protein excretion,SLEDAI score,anti-dsDNA antibody titers,serum albumin and complement C3 levels after treatment between two groups.Incidence of adverse events did not differ between the leflunomide and cyclophosphamide group.Conclusions Leflunomide combined with prednisone showed same efficacy compared with cyclophosphamide as induction therapy for lupus nephritis.Leflunomide might be an useful medicine in the induction therapy of lupus nephritis.