After studying this chapter, the student should be able to:
Understand the overall incidence and impact of nervous system tumors.
Identify common primary brain tumors in both the adult and pediatric populations.
Be able to describe common clinical presentations of primary brain tumors and recognize classic diagnostic features.
Identify common peripheral nervous system tumors.
Recognize tumors that commonly metastasize to the brain.
Recognize and describe common paraneoplastic syndromes.
Recognize common cancer-predisposing syndromes and familial tumor syndromes.
Nervous system tumors are a large and diverse group that can involve the brain, the meninges, the spinal cord, nerve roots, or peripheral nerves. In addition, there can be either primary nervous system tumors or metastatic spread of other primary cancers to involve the nervous system. In general, primary brain tumors and other nervous system cancers are relatively rare when compared to other cancers such as lung or breast cancer. However, despite their relative rarity, they are an important source of morbidity and mortality for patients. This chapter is not meant to be an all-inclusive review of nervous system tumors but rather will highlight key tumors and syndromes and will review common clinical presentations and basic diagnostic and treatment strategies.
Overall, brain tumors are uncommon, and according to the 2015 Central Brain Tumor Registry of the United States, they account for only 2% of all cancers. Meningiomas are the most common primary brain tumors (36.1%), followed by Glial cell tumors (25.8%), and pituitary tumors (15.1%) (Figure 25–1). The incidence of brain tumors varies by age, sex, and race, and there is an overall higher rate of nervous system cancers in individuals with certain predisposing genetic syndromes. Over the past 3 decades, the incidence and mortality of brain tumors have increased dramatically, especially in patients >75 years of age. Reasons for this may include improved diagnostic imaging, increased access to medical care, improved care for elderly patients, and/or changes in causal factors. Ultimately, more research is required to understand this observation.
Distribution of all primary brain and central nervous system tumors by histology, Central Brain Tumor Registry of the United States (CBTRUS) 2007 to 2011 (N = 343,175). (Reproduced with permission from Ostrom QT, Gittleman H, Liao P, et al. CBTRUS statistical report: primary brain and central nervous system tumors diagnosed in the United States in 2007-2011. Neuro Oncol. 2014 Oct;16 Suppl 4:iv1-63.)
A considerable amount of research has been devoted to identifying risk factors for nervous system cancers in order to understand why they occur and to discover better treatment options. Unfortunately, however, most brain tumors have no known cause. High-dose therapeutic ionizing radiation to the head has been associated with an increased risk for both meningiomas and glioblastomas (GBMs). In addition, there are certain hereditary genetic conditions that ...