Clinical features and management of primary malignant renal perivascular epithelioid cell tumor / 中华泌尿外科杂志

ABSTRACT

Objective To summary the pathological and clinical characteristics,treatments and prognosis of malignant renal perivascular epithelioid cell tumor (PEComa).Methods Between August 2013 and June 2017,8 cases of malignant renal PEComa were analysed respectively.Of all the patients,there were 4 males and 4 females,aged 27-65 years with the average of 46.3 years old.Three cases were detected in routine examination occasionally,three cases complained of intermittent back pain with fever,one presented with swollen and painful right hand and right foot,and one case presented with hematuria.CT or MRI examinations indicated the malignant lesions before the surgery.Clinical staging was performed with 2 cases of T1N0M0,1 case of T1 N0M1,2 cases of T2N0M0,1 case of T3M0M0,and 2 cases of T4N0M1.Three cases underwent radical nephrectomy,1 case underwent radical nephrectomy plus renal artery embolization,2 cases underwent partial nephrectomy,and 2 cases underwent nephrectomy plus inferior vena cava tumor thrombectomy.One case was treated with ifosfamide plus epirubicin after operation due to multiple distant metastases and 1 case was treated with oxaliplatin before the sugery because of excessive tumor diameter.None of the rest received any adjuvant therapy.Results Postoperative histopathological examination showed multiple nodules in reddish gray and yellow color,with soft texture and partial incomplete capsule.Microscopically,there were large atypical cell components,some of which were spindle shaped,with disordered cell arrangement,some of which were associated with a large amount of necrotic tissue,and abundant light eosinophil cytoplasm.Tissue components can be found thick-wall blood vessels,smooth muscle-like cells,and adipose tissue.Immunohistochemistry showed 4 cases were positive of HMB-45,4 of Melan-A,7 of SAM.Seven cases were negative of CK,6 of S-100 75％ (6/8) and Ki67 (10％-70％).Two cases died of multiple metastases (lung,bone,liver),1 case survived with tumor recurrence,with a follow-up from 14 to 60 months (mean 29 months).Conclusions Primary malignant renal PEComa is rare in practice with relative large diameter.The diagnosis depends on pathological findings,and radical nephrectomy is the first choice of treatment.It is easy to recur and metastasize after the operation.