Solitary fibrous tumors of pleura and lung: report of twelve cases

Abstract

Solitary fibrous tumors (SFTs) of pleura and lung are rare primary tumors that arise from the submesothelial tissue and usually show a benign clinical course. Immuno-histochemical analysis is used to make the diagnosis. We have reviewed our experience to obtain a better understanding of this disease. In this study, we reviewed 12 patients who had undergone a surgical resection for treatment of benign solitary fibrous tumors (SFTs) of pleura and lung during the period from 2006 to 2012. Following excision, the most essential characteristic on histopathology was nonatypical spindle-shaped tumor cells on a collagenous background. Keloid-type collagen, hypocellular and hypercellular areas could be observed in all the cases. On immuno-histochemical analysis, we found that mesenchymal markers such as CD34, bcl-2 and vimentin were positive, and S-100 protein and desmin were negative. In addition, Ki-67 was positive in approximately 5% of the tumor cells, but C-kit protein was not detected. If the result for CD34 was negative, expression of bcl-2 was positive. Complete resection was performed through thoracotomy, including 8 cases that involved video-assisted thoracic surgery (VATS). The postoperative courses were uneventful, and there was no recurrence during 3-65 (mean 25) months of follow-up. Complete resection of SFTs is usually curative. Morphological and pathological features are important in distinguishing them from other tumors and in predicting clinical behaviour.