A<unk> is a<unk> in the mediastinum, the cavity that separates the lungs from the rest of the chest. It contains the heart, esophagus, trachea, thymus, and aorta. The most common<unk>  masses are neurogenic<unk>  (20% of<unk> , usually found in the posterior mediastinum, followed by thymoma (15–20%) located in the anterior mediastinum. Lung cancer typically spreads to the lymph nodes in the mediastinum. The mediastinum has three main parts: the anterior mediastinum (front), the middle mediastinum, and the posterior mediastinum (back). Masses in the anterior portion of the mediastinum can include thymoma, lymphoma, pheochromocytoma, germ cell<unk>  including teratoma, thyroid tissue, and parathyroid lesions. Masses in this area are more likely to be malignant than those in other compartments. Masses in the posterior portion of the mediastinum tend to be neurogenic in origin, and in adults tend to be of neural sheath origin including neurilemomas and neurofibromas.
Mediastinal tumors
Tracheal tumor
Lung tumor
Airway obstruction
Lung nodule
Mediastinitis
Pleural disease
Lung cancer