162: Neurogenic Tumors of the Posterior Mediastinum

Introduction

Neurogenic tumors arise in tissues derived from the embryonic neural crest. Further classification is based on whether the tumor cell originates from nerve sheath, nerve cells (ganglia), paraganglia, or peripheral nerve (Table 162-1). In the thorax, the latter nerve is represented by the intercostal nerve. The chief impediment to understanding thoracic neurogenic tumors is the lack of uniformity in the nomenclature used in the published literature, and thus multiple descriptors exist at each taxonomic level (Table 162-2). This chapter relies on the nomenclature endorsed by the most recent revision of the World Health Organization classification of tumors derived from neural tissue.¹

Neural crest-derived tissues can be found throughout the body. In the thorax, neurogenic tumors are found most commonly in the posterior mediastinum (63%–96%).^1–6 In fact, neurogenic tumors account for 75% of all posterior mediastinal neoplasms.³ The epidemiology of neurogenic tumors depends primarily on whether the patient is an adult or a child. Although one-third of mediastinal tumors diagnosed and treated in children are neurogenic, the incidence is only 12% to 14% in adults.^7,8 Adults also have a lower rate of malignancy (5%–10% in adults compared with 40%–60% in children) (Fig. 162-1).^1,7 The most common neurogenic tumors in adults arise from the nerve sheath (e.g., neurilemmoma and neurofibroma), whereas in pediatric populations the cells of origin are the ganglia (e.g., ganglioneuroma and neuroblastoma) (Table 162-3).^1,9,10