[A case of carcinosarcoma of the lung].

A 63-year-old man was admitted to our hospital because of cough and slight fever up. A tumor shadow in right S6 and obstructive pneumonia was detected by X-ray and CT. Bronchoscopic study showed that right B6 bronchous was occluded by the tumor and in which malignant cell (squamous cell carcinoma suspect) were detected. Therefore right middle and lower lobectomy was performed. Histological examination of the resected specimen showed that the tumor was composed of poorly differentiated squamous cell carcinoma and abnormal spindle cell component. Both components of the tumor were mixed each other in part. Immunohistologically, malignant cell of sarcomatous elements were positively stained by vimentin and actine, but was not found such as osteosarcoma or rabdomyosarcoma. He was diagnosed as so-called carcinosarcoma of the lung.