[Primary sarcoma of the pulmonary artery].

On the basis of one personal case of leiomyosarcoma, the various anatomicoclinical features of sarcomas of the pulmonary artery are summed up. They most often produce a picture of severe pulmonary embolism that is resistant to all treatments; the lesion most often is a hilar mass without any associated bronchoscopic abnormality. Angiograms are not always easily interpreted, and the modern imaging techniques (ultrasound, computed tomography, and above all MRI) can best lead to the preoperative diagnosis, although this lesion is unfrequent.