Huge Localized Fibrous Tumor of the Pleura Resembling a Mediastinal Tumor: Report of a Case

A 67-year-old man was admitted to our hospital because of an abnormal chest echoic lesion detected incidentally by echocardiography. A chest roentgenogram showed the presence of a giant mass, and computed tomography of the chest confirmed the presence of a mass with a nonhomogeneous density in the left mediastinum, just adjacent to the left ventricle of the heart. Percutaneous aspiration cytology of the mass showed benign fibrous cells and a small amount of lymphocytes. The preoperative diagnosis of the tumor suggested a thymoma, and the patient underwent a thoracotomy. A pedunculated tumor arose from the visceral pleura of the left upper lobe of the lung, and it was capsulated within the pleura. The tumor measured 15 × 12 × 8 cm in size and it was successfully resected. The pathological diagnosis of the tumor was benign localized fibrous tumor of the pleura.