Abstract
A 72-year-old woman was being followed for a polyp in the gall bladder, and an abnormal shadow was detected on abdominal computed tomography. The shadow was in the right costo phrenic angle and was diagnosed as a pleural effusion. Follow-up abdominal computed tomography showed that the shadow had grown over two years ; chest computed tomography with contrast medium showed that the abnormal shadow had an enhanced area. The patient underwent thoracoscopic surgery for diagnosis and treatment. The tumor protruded from the right lower lobe and was resected with a 2-cm surgical margin. On pathology, the tumor was diagnosed as a solitary fibrous tumor arising from the visceral pleura. Solitary fibrous tumor should be considered in the differential diagnosis of a lesion at the costo phrenic angle.
