Primary intrathoracic malignant fibrous histiocytoma and angiosarcoma.

Primary intrathoracic malignant fibrous histiocytoma and angiosarcoma are rare sarcomas constituting less than 0.2% of lung cancers. The typical imaging appearance is a large, well-circumscribed, non-cavitating, non-calcified, peripheral lung mass without hilar or mediastinal lymphadenopathy. Bronchoscopy and percutaneous needle aspiration are of limited value in differential diagnosis, and thoracotomy is warranted for definitive diagnosis.