Purpose To investigate the clinicopathologic features,molecular changes,treatment and prognosis of pulmo-nary artery intimal sarcoma.Methods Ten cases of pulmonary artery intimal sarcoma were collected and the clinical features analyzed,by using HE,immunohistochemistry EnVision meth-od,FISH,and review of relevant literature.Results There were 4 males and 6 females,with a male to female ratio of 1∶1.5.The patients were 33-75 years old with an average age of 55.7 years.The main clinical symptoms were chest tightness,shortness of breath(6/10),chest pain(5/10)and cough(3/10),hemoptysis(2/10),syncope(1/10),heart murmur(1/10).1 patient had a history of bilateral breast cancer,bilateral papillary thyroid carcinoma and invasive lung adenocarcinoma,1 patient had bilateral breast cancer and 1 patient had pulmonary embolism and cardiac myxoma.Preoperative imaging showed pulmonary embolism or lung tumor.Histological morphology showed that the tumor cells were fusiform or epithelioid,with ob-vious atypia.Some tumors differentiated into rhabdomyosarco-ma,angiosarcoma and leiomyosarcoma,and giant cells were seen in 2 cases.The tumor lacked specific immune markers,and the tumor cells expressed vimentin,Fli-1,SMA,MyogD1,Myoglobin,BCL-2,ERG,etc.Ki-67 proliferation index was a-bout 30％-70％.Fluorescence in situ hybridization was used to detect MDM2(4/5)and CDK4(1/1).All cases received surgical treatment,7 cases were followed up from 1 month to 17 months,and 4 cases of them had recurrence or distant metasta-sis.Conclusion Pulmonary artery intimal sarcoma is rare,without specific immune markers and with complicated gene changes.There is no standard treatment,and the prognosis is poor.