Summary

Solitary fibrous tumor is a rare tumor of the serosal membranes and it is accepted to be originated from submesothelial layer. It is usually located to pleura, mediastinum and lungs but its typical place of settlement is the base of the pleura. Our case was a 65 years old female having long term dispnea. A shadow was seen located to right lower zone at the PA chest x-rays. CT examination revealed circumscribed mass, measuring 8cm. in diameter, at the superior segment of right lung’s lower lobe, adjacent to the pleura. At the operation, a capsulated mass connected with a pedicule to lower lobe superior segment was totally excised. Histopathologically, the tumor was characterized by a proliferation of spindle or oval cells separated by bands of collagen. Immunohistochemically, tumor cells were stained positively for vimentin and CD34 but there was no reactivity for cytokeratin, S-100 and smooth muscle actin. In the light of all these findings, the final diagnosis was a solitary fibrous tumor. At one year follow-up, the patient has no clinical or radiological evidence of recurrence.