Primary intrathoracic malignant mesenchymal tumors: pictorial essay.

Primary mesenchymal intrathoracic tumors are unusual. They can originate from the lung, the pleura, or the mediastinal structures. These sarcomas have protean, nonspecific imaging features. This pictorial essay illustrates a large number of these tumors, describes the plain film findings, and emphasizes the contribution of the new imaging modalities. The cross-sectional display and the high contrast resolution computed tomography (CT) and the ability to image vascular structures and chest wall with magnetic resonance (MR) allow excellent delineation of tumor extent and assessment of chest wall or vascular invasion. Early recognition of recurrence or metastases can be facilitated. In rare instances, the intrinsic characteristics of the tumor allow a specific diagnosis.