Primary central nervous system lymphoma presenting as an isolated intramedullary spinal cord lesion: a case report.

Background: Intramedullary spinal cord lesions prove to be a diagnostic challenge due to their non-specific clinical and radiological presentation. There is a preference for empiric medical therapy, given the inherent risks of surgical intervention to the spine. These factors can lead to delay in diagnosis. Primary central nervous system lymphoma is a rare cause and presents with atypical features in the immunosuppressed patient, including a lack of response to steroid therapy. Case Description: We present a 64-year-old male patient with underlying sarcoidosis who reported progressive neuropathy with imaging showing a spinal cord lesion. Based on the above, multiple courses of empiric therapy were employed, including systemic steroids, chemotherapy and immunotherapy. Despite this, there was further clinical deterioration and interim imaging showed disease progression. The decision was made to perform open biopsy of the spinal cord lesion to aid diagnosis. Histological analysis diagnosed Epstein-Barr virus (EBV)-positive high grade large B-cell lymphoma. The patient received rituximab and methotrexate with radiological response but no clinical benefit. He continued to suffer treatment-related complications including encephalopathy and recurrent infections which eventually lead to death. Conclusions: Primary central nervous system lymphoma is an aggressive disease and failure to respond to empiric treatment should prompt clinician's to consider biopsy for definitive diagnosis. A lack of response to steroids does not exclude lymphoma.