[Progredient "pulmonary thromboembolism" in spite of sufficient anticoagulant therapy?]

A 43-year-old woman presented with persistent dry cough and exertional dyspnoea for about 6 months. An outpatient CT scan of the chest led to the diagnosis of pulmonary thromboembolism.

The echocardiography showed signs of right ventricular load. Phlebothrombosis, thrombophilia or an active malignant disease were excluded.

An anticoagulant therapy was started in the hemodynamically stable patient. She was discharged in good condition. Four weeks later the patient was readmitted with worsening of symptoms. The CT scan showed progression of the findings in spite of sufficient anticoagulant therapy. Echocardiography revealed an increase of the right ventricular load. A systemic thrombolysis with 100 mg alteplase followed, but without any change. Subsequently, the suspicion of an intraluminal growing tumorous mass was confirmed. A tumor-endarterectomy with reconstruction of the left pulmonary artery together with a pericardial patch and an extensive pneumonectomy on the right were performed. Histopathologically and immunohistochemically a pulmonary artery sarcoma with the differentiation of a leiomyosarcoma was diagnosed.

The primary pulmonary artery sarcoma is a rare disease and pulmonary thromboembolism must be considered for differential diagnosis. In the CT scan a low-attenuation filling defect occupying the entire luminal diameter of the pulmonary artery, expansion of the involved arteries or extraluminal tumor extension can lead to a suspected diagnosis. Furthermore in case of a progression of the findings under sufficient anticoagulant therapy a primary pulmonary sarcoma has to be considered as differential diagnosis. Complete surgical resection offers the only chance of cure.