Primary central nervous system lymphomas: clinicopathologic and immunohistochemical analysis of 30 cases

Aims and background: Primary Central Nervous System lymphomas are attracting mounting interest because of their increasing incidence in an immunocompetent population and as sporadic tumors. A new lymphoma classification has been proposed, based on new morphologic entities and on advanced immunonologic and molecular techniques. Methods and results: The study concerns the clinical and pathologic characterization of 30 cases of primary central nervous system non-Hodgkin's lymphomas in non-HIV patients using a wide monoclonal antibodies panel. Comparative evaluation of effectiveness and reliability between surgery and stereotactic biopsies was made according to Kiel and Real lymphoma classifications. There were 24 high-grade and only 3 low-grade lymphomas. Three stereotactic biopsies were not diagnostic. Conclusions: Stereotactic procedures were confirmed as the most immediate and least aggressive approach to CNS tumors, but inadequate sampling caused a deadlock to a full lymphoma diagnosis, which requires immunohistochemical and sometimes also molecular studies. However, it should be stressed that morphologic criteria (tumor cell cytology and neoplastic cuffing of the vascular walls) maintain their diagnostic effectiveness.