[A case of primary pulmonary leiomyosarcoma showing rapid growth and fatal outcome]

An 80-year-old man was admitted to our hospital with a 4.0 x 2.0 cm shadow accompanied by calcification, found on chest CT scans on a health check. The shadow was located in the left lower lobe (S10), and was attached to the pleura. A transbronchial biopsy did not yield a definitive diagnosis. A percutaneous needle biopsy yielded a diagnosis of leiomyosarcoma. A general examination did not show any metastatic lesions in other areas. However, the tumor grew rapidly, with pleural effusion, and therefore he was treated only by palliative therapy. He died from respiratory failure 90 days after onset. The primary site of the tumor was determined to be intrapulmonary area by radiographic and autopsy findings. We report a rare primary pulmonary leiomyosarcoma showing rapid growth and fatal outcome.