[A resected case of solitary fibrous tumor of the pleura].

A 45-year-old female with solitary fibrous tumor (SFT) of the pleura was reported. Chest X-ray and CT scan on admission showed a large tumor in the right thoracic cavity. A preoperative needle biopsy was performed. The microscopic appearance of biopsied specimen revealed many spindle cells. And an immunohistochemical study was positive for CD 34 and negative for keratin, epithelial membrane antigen, alpha-smooth muscle actin, S-100 protein. So SFT was strongly suspected and an operation was performed. A tumor arised from the visceral pleura of right middle lobe and was pedunculated. The tumor was 13 x 10 x 7.5 cm in size. An immunohistochemical study of the tumor was positive for CD 34, and negative for SMA, ki-67. From these immunohistochemical stainings and microscopic findings, the tumor was diagnosed as SFT. An immunohistochemical study of the tumor seems to be very useful for the diagnosis of SFT.