[Pleural solitary fibrous tumor from diaphragm, being suspected of liver invasion; report of a case].

We report a case of solitary fibrous tumor (SFT) from diaphragmatic pleura. A 71-year-old female was admitted to our hospital because of an abnormal shadow on chest X-ray. A preoperative imaging study revealed a mass on her right diaphragm. At thoracoscopic exploration, the tumor was found to originate from diaphragm and was suspected of liver invasion. The conversion to open thoracotomy was introduced to perform appropriate surgical procedure. Pathological examination revealed proliferation of spindle cells and collagen fibers. Immuno-histochemical findings showed positive immunostaining for cell differentiation (CD) 34 and vimentin. The tumor was diagnosed as SFT with malignant potential.