Cerebrospinal fluid (CSF) cytology: current status and diagnostic applications.

Cytologic evaluation of cerebrospinal fluid (CSF) is an effective means for diagnosing many disorders involving the central nervous system (CNS). Interpretation of these samples requires an understanding of the spectrum of neurologic diseases which involves the subarachnoid space, either primarily or secondarily, as well as familiarity with the cytologic characteristics of these lesions. Here the clinical features and cytologic presentation of common conditions which can be diagnosed by CSF cytology are reviewed. Preparatory methods for CSF examination are discussed and normal and reactive conditions involving CSF, lymphoma, leukemia, meningeal carcinomatosis and the subarachnoid spread of primary brain tumors are described and illustrated.