Primary lymphoma of the central nervous system.

Primary intracranial lymphoma usually remains localized to the central nervous system, and aggressive radiotherapy will prolong some patients' remission and perhaps cure them. Although the lesion is usually believed to arise from histiocytes or reticulum cells, at least some of the neoplasms are of B-lymphocyte origin. Provisional diagnosis occasionally may be possible by identifying lymphoma cells in the cerebrospinal fluid by using the cytocentrifuge. The use of computed tomography of the head may decrease the need of arteriography for tumor localization.