A 67-year-old male was diagnosed with pulmonary embolism and treated with anticoagulants. Half a year later CT of the chest showed growth of the embolism and that pleural fluid and pleural noduli had appeared. A 18FDG-PET-CT showed uptake in these abnormalities and in several bones. Bone biopsy showed a leiomyosarcoma. The patient was diagnosed with metastasized pulmonary artery sarcoma.