Case Presentation:

A 44‐year‐old African American man without a significant medical history presented to an outside hospital with 10 days of nausea, vomiting, weakness, and confusion. He was hydrated, stabilized, and subsequently discharged. Over the next month, he developed worsening fatigue, weakness, ataxia, diplopia, and headaches. He was readmitted, and a contrast MRI showed nodular leptomeningeal enhancement. A lumbar puncture revealed elevated protein and lymphocyte predominance in the cerebrospinal fluid. He was diagnosed with neurosarcoidosis and was started on corticosteroids. A neurosurgical evaluation was obtained for a leptomeningeal biopsy, but the biopsy was deferred given improvement in symptoms on corticosteroids. He remained on steroids, but weeks later was readmitted for worsening weakness, diplopia, and altered mental status. A CT scan of the brain revealed hydrocephalus, and he was transferred to our medical center for a ventricular‐peritoneal shunt procedure. During the shunting procedure, CSF was sent for cytology, and results revealed primary CNS lymphoma.


Primary CNS lymphoma (PCL) is uncommon and can affect the brain, eyes, leptomeninges, spinal cord, and nerves. Although this patient was otherwise healthy, immunodeficiency is an important risk factor. Patients may present with headache, seizures, ocular symptoms, ataxia, and personality change. Contrast‐enhanced MRI is the preferred imaging modality. Treatment options include chemotherapy, radiation, and steroids. Corticosteroids produce tumor regression; however, once corticosteroids are discontinued, patients often relapse quickly. The clinical manifestations of PCL are subtle and require a high degree of clinical suspicion. Often PCL can de difficult to distinguish from other neurologic or systemic diseases. Neurosarcoidosis is a disease that can present identically to PCL. Patients can present with cranial neuropathies, neuroendocrine dysfunction, mass lesions, encephalopathy, seizures, or psychiatric symptoms. Contrast MRI demonstrates meningeal enhancement and multiple white matter lesions. The cerebral spinal fluid usually has elevated protein, IgG, and ACE levels. The treatment for neurosarcoidosis is corticosteroids.


This case illustrates 5 important teaching points. First, almost without exception, if neurosarcoidosis is suspected and no systemic disease is identified, a biopsy should be obtained to establish the diagnosis. Second, corticosteroids should be withheld until a definitive diagnosis is made to prevent diagnostic inaccuracy. Third, corticosteroids can cause transient improvement in PCL as steroids are part of the chemotherapeutic regimen for lymphoma treatment. Fourth, clinicians should be cautious about forgoing a diagnostic procedure because of a patient's improvement with corticosteroid therapy. Last, in the medical literature, PCL and neurosarcoidosis are 2 diseases easily mistaken for each other.

Author Disclosure:

J. Talavera, none; P. Aronowitz, none.