Mediastinal Tumors

Mediastinal tumors comprise both benign and malignant neoplasms. Primary mediastinal tumors arise from thymic, neurogenic, germinal or lymphatic tissue with thymomas, neurogenic tumors and benign cysts making up the vast majority. The location of the mass is key to the diagnosis with each tumor type having a definite predilection. Mediastinal tumors are associated with a wide spectrum of clinicopathological features and paraneoplastic syndromes. The presentation may vary from being asymptomatic to symptoms due to compression or infiltration of surrounding vital structures and secretory or immune-mediated symptoms. Evaluation with thorough physical examination, supplemented by tumor marker analysis (AFP, beta-HCG, LDH) and cross-sectional imaging, is critical for diagnosis and tumor characterization. Multidisciplinary management is mandatory for this heterogeneous group of tumors. Surgery is the mainstay of treatment for neurogenic tumors, early stage thymomas and mature teratomas, while systemic therapy plays an important role as primary therapy in seminomas and nonseminomatous germ cell tumors, with surgery indicated only for residual tumors. Radiotherapy mainly plays an adjunct role and is used as local therapy for small seminomas and as adjuvant therapy after incomplete resection in thymomas. The prognosis of this diverse group of tumors is variable and multifactorial. This chapter provides a brief overview of the approach toward management of mediastinal masses.