["Walking pneumonia" in primary sarcoma of the pulmonary artery].

A 74-year-old man suffered from symptoms of a left upper lobe pneumonia. Additional retrosternal masses were proved. Progression in the left upper lobe occurred in spite of antibiotic therapy; infiltrations of the right lower lobe were seen. No germs could be identified. Bronchoscopy and mediastinoscopy showed no pathological findings. His general health became worse, and the patient died under the clinical diagnosis of "wandering pneumonia" with finally suspicion of fulminant pulmonary artery embolism. Autopsy findings revealed an advanced stage of pulmonary artery sarcoma with myocardial infiltration and metastases in both kidneys and thyroid gland. General manifestation of pulmonary artery sarcoma usually are symptoms similar to those caused by pulmonary artery embolism with obstruction of pulmonary arterial flow. The unusual constellation of clinical findings similar to colliquating pneumonia results in secondary infection due to tumorous pulmonary infarction. The difficulties in diagnosis by biopsy are caused by primary intravascular growth of the neoplasms. Therefore early diagnosis in an operable tumor stage by means of CT, MR, and angiography is very important.