[Primary leiomyosarcoma of the pulmonary artery. Apropos of a case]

A case of leiomyosarcoma of the pulmonary artery in a 64-year old man without previous cardiovascular disease is reported. The clinical picture, which comprised episodes of paroxysmal dyspnoea associated with acute cor pulmonale, suggested pulmonary embolism. Radioisotope perfusion study and pulmonary angiography seemed to confirm this diagnosis, but no improvement was obtained with a prolonged thrombolytic treatment. The presence of a median mass at CT led to exploratory thoracotomy and to the finding of a tumour in the pulmonary artery, which turned out to be a leiomyosarcoma. The disease rapidly took an unfavourable course. Comparison of this case with data from the literature showed that primary tumours of the pulmonary artery are extremely rare, that they are diagnosed with difficulty and often at a late stage and that their prognosis is usually very sombre.