In general, CNS lymphoma is an infiltrating lesion that appears diffuse or as a mass lesion with neurologic signs and symptoms that are non-specific. Rarely, it may appear without a mass lesion and only a monoclonal cell population in the cerebral spinal fluid is detectable. There may be headache that is often diffuse and general malaise due to increased intracranial pressure with a slowly developing confusional state clinically similar to encephalitis. When the orbits are involved, there may be ocular pain or visual disturbances including uveocyclitis and visual field abnormalities. Specific neurologic findings may be helpful in localization to a specific region of the brain.
Initial evaluation varies depending on the immunologic status of the patient.
In immunocompetent and immunosuppressed patients, recent studies in adults with primary CNS lymphoma indicate differing early diagnostic evaluations. Adults with AIDS who develop CNS lymphoma have a large incidence of orbital and meningeal involvement with dissemination to other organ systems including bone marrow. However, in the immunocompetent patient, primary CNS lymphoma appears to be limited to the neuro-axis, with rare involvement of the bone marrow and visceral organs. MRI of the cranium provides essential information at diagnosis as to the extent of dissemination and overall mass size of the lesion. CT scan may demonstrate an area of low signal that enhances homogeneously with IV contrast.