Meningeal dissemination in primary CNS lymphoma: diagnosis, treatment, and survival in a large monocenter cohort.

The frequency of meningeal dissemination (MD) in primary CNS lymphoma (PCNSL), its prognostic impact, and optimal management have not been defined thus far. In 69 of 92 (75%) immunocompetent patients, primarily diagnosed with PCNSL at our institution between January 1994 and February 2007, cerebrospinal fluid was analyzed for MD. MD was found by cytomorphology in 7/63 (11%), by immunophenotyping in 1/32 (3%), and by PCR of the IgH CDR III region in 6/37 (16%). Neuroradiologic examination revealed MD in 3 of 69 patients (4%). Median event-free survival (EFS) of patients with MD diagnosed by any of the methods was 26 months, of those without MD 34.1 months (P = .24); median overall survival (OAS) of these two patients' groups was 45.5 and 42.5 months, respectively (P = .34). Patients with cytomorphologic proof of MD had a median EFS of 15.4 months and OAS of 18.5 months, those without MD 34.3 and 45 months (P = .018 and .017, respectively). We found a low frequency of MD despite the use of putatively sensitive diagnostic methods. No impact on outcome was seen for MD, diagnosed by any of the methods used; however, patients with cytomorphologic proof of MD had a significantly shorter median EFS and OAS.