From the archives of the AFIP: Localized fibrous tumor of the pleura.

Eighty-two localized fibrous tumors of the pleura (LFTP) were reviewed retrospectively for the clinical, pathologic, and radiologic findings. Forty-four women and 38 men ranged in age from 17 to 78 years (mean, 54.7 years). Sixty-four benign LFTP ranged in size from 2 to 30 cm (mean, 13.2 cm), and 18 malignant tumors ranged from 3 to 23 cm (mean, 14.4 cm). Forty-eight patients (60%) presented with symptoms. Radiographs of 76 patients demonstrated solitary masses occupying or extending into the inferior hemithorax (79%). Computed tomography (CT) of 78 lesions demonstrated lobular masses (83%) that formed at least one acute angle (96%) or only acute angles (65%) with the adjacent pleura. Heterogeneous lesion attenuation was documented in 88% of enhanced and in 68% of unenhanced CT scans. Contrast enhancement was common (62% of cases). Magnetic resonance (MR) imaging of 18 lesions demonstrated heterogeneous signal intensity on both T1- and T2-weighted images (78% and 83%, respectively). Multiplanar MR imaging allowed visualization of the diaphragm and documentation of an intrathoracic mass in all cases. LFTP are solitary lobular heterogeneous masses that occur in symptomatic adults and often affect the inferior hemithorax. Malignant lesions are radiologically indistinguishable from those with benign histologic characteristics. Radiographic and CT features characteristic of pleural location are typically absent.