Central Nervous System Tumors

The central nervous system (CNS) is the part of the nervous system comprising the brain and the spinal cord. CNS tumors are a heterogeneous group of tumors with variations in their epidemiology, presentation, clinical and pathologic features, management, and prognosis. As a group, they represent the most common tumors that develop in children (commonly gliomas). In adults, however, metastases or secondaries from another primary site are the most common type of brain tumor. The most common types of primary brain tumors are gliomas, which arise from glial cells which are nonneuronal cells that maintain homeostasis in the CNS. These tumors, which may be low-grade or high-grade (commonly), are infiltrative by nature and managed by maximal safe tumor resection followed by adjuvant radiotherapy and chemotherapy, as indicated. Elderly patients with high-grade gliomas have a grave prognosis. Other CNS tumors may include meningioma, ependymoma, pituitary adenoma, craniopharyngioma, and primitive neuroectodermal tumors, among others. Most are managed by a combined modality approach of surgery and radiochemotherapy. Stereotactic radiotherapy may be used for small lesions. Brain metastases are also best managed by surgery and adjuvant radiotherapy. Many patients have a poor performance status or additional widespread systemic disease, and they are best suited to steroids and supportive care only.