Primary Mediastinal Neoplasms

The mediastinum can be the site of a variety of neoplastic conditions that can include both benign and malignant entities. Most neoplasms of the mediastinum are metastases, typically from lung cancer, although extrathoracic neoplasms such as breast cancer and melanoma have a predilection for spread to the mediastinum. Primary neoplasms of the mediastinum are uncommon, and whereas the majority in adults are benign, those in children tend to be malignant. In terms of primary neoplasms, the most common prevascular or anterior compartment neoplasms include thymomas, teratomas, and lymphomas. Neoplasms of the visceral or middle compartment are typically congenital cysts, including foregut and pericardial cysts, whereas those that arise in the posterior or paravertebral compartment are often tumors of neurogenic origin. This chapter discusses mediastinal neoplasms, with particular emphasis on those primary neoplasms that are frequently encountered in an oncologic medical practice. Computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT will be emphasized as the tools of choice in the characterization of these neoplastic entities to help referring physicians, oncologists, and surgeons deliver proper care and follow-up of afflicted patients.