Neurological misdiagnoses of lymphoma.

BACKGROUND Lymphoma of the nervous system is rare and usually involves the brain, spinal cord, or peripheral nerves. Hence, it has varied clinical presentations, and correct diagnosis is often challenging. Incorrect diagnosis delays the appropriate treatment and affects prognosis. We report 5 patients with delayed diagnosis of lymphoma involving the central and/or peripheral nervous system, initially evaluated for other neurological diagnoses. We also discuss the challenge of diagnosis and appropriate testing. METHODS Retrospective review of 2011-2019 records of patients with confirmed nervous system lymphoma diagnosed in a tertiary care medical center. RESULTS We present 5 adult patients initially evaluated for inflammatory myelopathy, inflammatory lumbosacral plexopathy, atypical parkinsonism, and demyelinating disease of the CNS. Final diagnosis of the nervous system lymphoma was delayed by 4 to 18 months and was based on tissue biopsy in 4, and on CSF and bone marrow examination in 1 patient. CONCLUSIONS Lymphoma may imitate various central and peripheral nervous system disorders. We suggest several red flags that indicate the need to consider lymphoma, including subacute but progressive symptomatic evolution, painful neurological deficit, unclear clinical diagnosis, and transient steroid responsiveness. Correct diagnosis often requires a combination of diagnostic tests, while pathology testing is crucial for early diagnosis and is strongly recommended in the appropriate clinical setting.