Making the diagnosis of secondary CNS involvement in lymphoma can be difficult due to unspecific signs and symptoms, limited accessibility of brain/myelon parenchyma and low sensitivity and/or specifity of imaging and cerebrospinal fluid (CSF) examination currently available. Areas covered: MRI of the total neuroaxis followed by CSF cytomorphology and flow cytometry are methods of choice when CNS lymphoma (CNSL) is suspected. To reduce the numerous pitfalls of these examinations several aspects should be considered. New CSF biomarkers might be of potential diagnostic value. Attempts to standardize response criteria are presented. Expert commentary: Diagnosing CNSL remains challenging. Until diagnostic methods combining high sensitivity with high specifity are routinely introduced, high level of awareness and optimal utilization of examinations currently available are needed to early diagnose this potentially devastating disease.
Keywords: Secondary CNS lymphoma; cerebrospinal fluid cytomorphology; cerebrospinal fluid flow cytometry; meningeal; neuroaxis MRI; novel markers; parenchymal; response criteria.