Anterior Mediastinal Lesions
Middle Mediastinal Masses
Uncommon Thoracic Tumors
The differential diagnosis of a mediastinal mass is facilitated by identifying its location within the mediastinal compartments (ie, anterior, middle, posterior). In addition, radiologic features, clinical context, and temporal course are important parameters to consider. Approximately 25% to 30% of mediastinal masses occurring in adults are malignant, a higher portion in the anterior mediastinum and in children. Overall, the most frequent mediastinal lesions are thymoma, neurogenic neoplasms, lymphomas, and foregut cysts. CT scanning is the most important imaging procedure and can define the density of the mass and effect on adjacent structures. A confident diagnosis sometimes can be established based on characteristic CT scan features. MRI may be useful in patients with contraindication to the use of iodinated IV contrast or when additional characterization of musculoskeletal or neurovascular anatomy is needed.
There are many types of uncommon to rare tumors that may be encountered in the thorax. Among these, more frequently encountered tumors include the carcinoid tumor, salivary gland type carcinomas, and hamartoma. Bronchial carcinoid tumors are malignant neoplasms with neuroendocrine differentiation and can be associated with ectopic hormonal syndromes. Mucoepidermoid carcinoma and adenoid cystic carcinoma are the most common forms of salivary gland-type carcinomas seen in the thorax, usually involving the trachea or major bronchi. Hamartoma is a benign tumor-like malformation composed of abnormal and disorganized mixture of tissue elements. Hamartoma is the most common benign neoplasm to occur in the lung, accounting for approximately 75% of all benign lung tumors and 4% of solitary pulmonary nodules.Objectives
Discuss the anatomic compartments of the mediastinum.
Discuss the diagnostic approach to mediastinal lesions and management options.
Discuss uncommon intrathoracic neoplasms.