[Analysis of surface markers on cerebrospinal fluid-producing cells. Contribution to the differential diagnosis of intrathecal lymphomas].

For differentiating between inflammatory and neoplastic intrathecal lymphopleocytosis, analysis of CSF cell surface markers was employed in two patients. In one case, diagnosis of intrathecal spreading of a previously not diagnosed lymphoma was established by identifying a uniform population of CALLA-negative (CALLA = common acute lymphoblastic leukaemia antigen) lymphocytes carrying kappa light chains, which reacted with an anti-B monoclonal antibody. In the second case, cytological examination of CSF showed atypical lymphoid cells as well as lymphoblasts and numerous mitoses. On the other hand, analysis of the CSF cell surface markers revealed a typical inflammatory reaction pattern in which antibody-positive inducer (helper) T-lymphocytes predominated. This pointed to inflammatory lymphopleocytosis as likely diagnosis.