<正> Three cases of pulmonary leiomyosarcoma were presented. The characteristic clinical features were described with review of literature- In comparison with bronchogenic carcinoma

the leiomyosarcoma has some characteristics: 1) On chest X-ray

it usually appears as a sharply demarcated

even density round mass

growing rapidly within the lung

it unusually accompanies with hilar or mediastinal lymph node metastasis; 2) The preoperative cytological or pathological diagnosis is difficult either by sputum smear or by bronchoscopic biopsy or by fine needle percutaneous aspiration biopsy; 3) Pathological differential diagnosis of leiomyosarcoma of lung from anaplastic lung cancer is difficult. In conclusion

the primary pulmonary leiomyosarcoma is a rare malignant tumor

detecting the present illness seriously

paying attention to the chest X-ray films characterize

early surgical resection is the only way to get diagnosis and effective treatment method.