Tumors of the Central Nervous System (I)

The word tumor is used in this book to designate not only lesions that grow as a result of uncontrolled cell division, such as neoplasms, but also masses that increase in volume either by the accumulation of secretory substances, as is true of cysts, or by progressive incorporation of adjacent structures into a congenital deformity, such as angiomatous malformations. The common features of almost all tumors discussed here are (a) the localized or focal nature of the neurologic deficit(s) induced by the lesion and (b) the time-dependent worsening of the symptoms that is ascribed to the expanding volume of the growth and the effects of the surrounding edema. Tumors that produce neurologic deficits or symptoms are not restricted to those that originate within the brain and spinal cord. Some of these tumors derive from bone, meninges, and other tissues, such as the spinal epidural fat.