[A case of pyothorax-associated pleural angiosarcoma diagnosed by autopsy].

A 76-year-old man with a dry cough visited our hospital in June 2006. A chest X-ray showed opacification of the left hemithorax and CT demonstrated a soft tissue mass with pleural calcification. At first, we considered he had acute bronchitis with an old tuberculous pyothorax. But, his condition deteriorated with the additional complaint of a left chest pain and shortness of breath in September 2006. Consequently, he was admitted to our hospital. CT demonstrated that the soft tissue mass was growing and was invading the left rib and submammary tissue. Neither CT nor sonographically guided fine needle biopsies and cytological examinations were helpful in diagnosing this disease. He died of respiratory failure 2 months after admission. Autopsy revealed pyothorax and a hemorrhagic tumor from the left side of the thoracic cavity to the chest wall. Microscopic examination showed that atypical cells had proliferated and formed vascular structures, which were stained positively with anti-factor VIII antibody. Finally, the diagnosis was made of pyothorax-associated pleural Angiosarcoma. Angiosarcoma is rare and difficult to diagnosis, however, we have to keep in mind the presence of disease pyothorax-associated pleural angiosarcoma.