Neuroborreliosis and CNS lymphoma: what is the nexus?

Primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare type of non-Hodgkin lymphoma (NHL) manifesting in the brain, spinal cord, cerebrospinal fluid and/or eyes, in the absence of systemic manifestations. With an increasing incidence and a 30% 5-year overall survival if promptly treated, timely diagnosis and subsequent treatment is paramount. The typical MRI appearance for PCNSL is a solitary or multiple T2-hypointense, homogeneous gadolinium-enhancing lesion with restricted diffusion. Dexamethasone treatment might compromise and delay the diagnosis. Hallmark of treatment is induction with intravenous high-dose methotrexate consisting polychemotherapy followed by consolidation treatment. Consolidation treatment consists of either whole brain radiotherapy (WBRT) or autologous stem cell transplantation (ASCT). Given the (cognitive) side effects of WBRT, ASCT is increasingly being used as the first choice of treatment.

Cerebrospinal Fluid Cytology of Lyme Neuroborreliosis: A Report of 3 Cases with Literature Review

Lyme disease can affect the central nervous system causing a B-cell-predominant lymphocytic pleocytosis. Since most reactions to infection in the cerebrospinal fluid (CSF) are typically T-cell predominant, a B-cell-predominant lymphocytosis raises concern for lymphoma. We present 3 Lyme neuroborreliosis cases in order to illustrate the challenging cytomorphological and immunophenotypic features of their CSF specimens. Three male patients who presented with central nervous system manifestations were diagnosed with Lyme disease. The clinical presentation, laboratory tests, CSF cytological examination and flow-cytometric studies were described for each case. CSF cytology showed lymphocytic pleocytosis with increased plasmacytoid cells and/or plasma cells. Flow cytometry showed the presence of polytypic B lymphocytes with evidence of plasmacytic differentiation in 2 cases. In all cases, Lyme disease was confirmed by the Lyme screening test and Western blotting. In such cases of Lyme neuroborreliosis, flow cytometry of CSF samples employing plasmacytic markers and cytoplasmic light-chain analysis is diagnostically helpful to exclude lymphoma.