B-cell lymphoma infiltration of cerebrospinal fluid with minimal symptoms and benign course.

We report a patient diagnosed with a B-cell lymphoma after detecting monoclonal B-cells in the cerebrospinal fluid (CSF) and who had only minimal symptoms and a benign course. A 46-year-old man experienced three transitory episodes with neurological symptoms. On examination papilledema in both eyes was found. Flow cytometry (FACS)-analysis detected monoclonal B-cells in the CSF as well as in the peripheral blood and the bone marrow. Results were consistent with a low-risk lymphoma, most probably a marginal zone B-cell lymphoma. Interestingly, our patient had no progressive clinical symptoms and remained without specific therapy during 36 months of follow-up. Nevertheless, CSF-analysis led to the diagnosis of the B-cell lymphoma.