neoplasm of mediastinum

Mediastinal tumors

A mediastinal tumor is a tumor in the mediastinum, the cavity that separates the lungs from the rest of the chest. It extends from the sternum to the spinal column. It contains the heart, esophagus, trachea, thymus, and aorta. The mediastinum has three main parts: the anterior mediastinum (front), the middle mediastinum, and the posterior mediastinum (back). Tumors in the anterior portion of the mediastinum can include thymoma, lymphoma, germ cell tumors including teratoma, thyroid tissue, and parathyroid lesions. Masses in this area are more likely to be malignant than those in other compartments. Middle mediastinal tumors are less common and refer to cardiac or neurogenic tumors. 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 shwannomas and neurofibromas. The most common mediastinal masses are thymoma (20% of mediastinal tumors), usually found in the anterior mediastinum, followed by neurogenic tumor (15–20%) located in the anterior mediastinum. Adults usually present with cancers of the anterior mediastinum and children usually present with cancers of the posterior mediastinum. Other conditions that can cause mediastinal enlargement includes aortic aneurysms, lymphadenopathy, cysts, inflammation, and abscesses.