Most pleural neoplasms are metastatic in origin. Primary tumors of the pleura can be categorized as diffuse or localized. Diffuse malignant mesothelioma is more common, is related to asbestos exposure, and is associated with a poor prognosis. Localized mesothelioma is called localized fibrous tumor of the pleura (LFTP; also known as solitary fibrous tumor of the pleura); this neoplasm is less common, has a controversial histogenesis, and is unrelated to asbestos exposure.
LFTPs exist in benign and malignant forms. Only rarely is the localized fibrous tumor invasive or does it cause local recurrence after resection. The ratio of benign to malignant tumors is 7:1. The diagnosis of LFTP is important because the tumor is potentially resectable for cure despite its typically large size. In many cases, resection can repeatedly be used to treat recurrence, although usually with increasing difficulty.
Usually, LFTP is discovered incidentally on chest radiographs. Findings from computed tomography (CT) scanning and magnetic resonance imaging (MRI) can suggest the diagnosis of LFTP. However, histopathologic examination is needed for a definitive diagnosis.
Chest radiographic findings are nonspecific, and the lesion can sometimes be obscured by associated pleural effusion. CT and MRI scans may show characteristic findings that are suggestive of LFTP but that are not always pathognomonic. The pleural origin of large lesions can be difficult to detect, especially on chest radiographs and even on CT and MRI scans.
An example of a benign LFTP is shown in the images below.
Posteroanterior chest radiograph in a 70-year-old woman who presented with chest discomfort. A well-circumscribed, pleural-based mass is seen in the upper left hemithorax. The angle between the mass and the chest wall is obtuse. The lesion was resected and found to be a benign localized fibrous tumor of the pleura.
Lateral chest radiograph in a 70-year-old woman who presented with chest discomfort (same patient as in the previous image).
Chest computed tomography (CT) scans in a 70-year-old woman who presented with chest discomfort demonstrate a pleural, noncalcified soft-tissue mass with smooth, lobulated margins (same patient as in the previous 2 images). The mass enhances slightly more than the soft tissue of the chest wall. No evidence of chest wall invasion is seen.