Mesenchymal Tumors of the Mediastinum

Mesenchymal tumors of the mediastinum are relatively rare; however, almost all types of mesenchymal lesions have been reported in this anatomic compartment. This includes vascular tumors, fibroblastic/fibrohistiocytic tumors, neurogenic tumors, myogenic tumors, lipomatous tumors, bone and cartilaginous tumors, and other tumors of uncertain etiology or histogenesis. These tumors cover the spectrum from benign to malignant neoplasms. The anatomic division of the mediastinum into three compartments, anterior, middle, and posterior, is helpful in certain instances when approaching these tumors; for example, neurogenic tumors are known to preferentially arise in the posterior mediastinum. In most cases these tumors share similar histologic and molecular genetic alterations to their soft tissue counterparts. Clinically the tumors may behave in slightly different manner as these lesions may sometimes grow and displace thoracic structures before becoming symptomatic. The diagnosis of these tumors often requires clinical, radiologic, and histologic correlation and in many cases will require ancillary diagnostic testing to secure the diagnosis.