Clinical manifestation of central nervous system tumor.

Tumors of the brain and spinal cord (central nervous system, CNS) are rare when compared with other sites and other diseases that can affect the length of an individual's life. However, about 20,000 new cases of primary CNS tumors are diagnosed in the United States each year, not an insignificant number. The CNS is "locked" inside a rigid and nonexpandable calvarium (except in newborns and young children); therefore, any new growths (primary or secondary) can only grow at the expense of the structures already inside the skull or spinal column. The symptoms and signs or clinical manifestations of CNS tumors depend on the location and the growth rate of these tumors. Symptoms include general nonlocalizing and focal symptoms and signs. General signs, which reflect the increase in intracranial pressure, include drowsiness, confusion, headache, nausea, vomiting, sixth nerve palsy, papilledema, generalized seizures, and cognitive impairment. Focal signs and symptoms reflect the effect of the tumor on specific structures. Special imaging techniques (such as computed tomography, magnetic resonance imaging, and positron emission tomography) are essential for the localization of the lesion and for image-guided brain biopsies. The handling of these tiny biopsies often presents significant diagnostic challenges, especially at the time of frozen section examination.