Primary intramedullary spinal cord lymphoma

Among the rare causes of myelopathies is primary intramedullary spinal cord lymphoma (PISCL). As PISCL is often underrecognized, delaying appropriate treatment, we sought to describe its presentation, imaging characteristics, and outcomes.

Mayo Clinic medical records, lymphoma database, and autopsies from 1996 to 2009 were searched. Inclusion criteria were clinical myelopathic presentation, intramedullary spinal cord abnormalities, and pathologically confirmed CNS lymphoma. Exclusion criteria were extramedullary lymphoma, secondary intramedullary lymphoma, or other myelopathic etiology. Clinical features, diagnostic methods, neuroimaging, treatment, and outcomes were assessed.

The 14 patients' median age at presentation was 62.5 years (range 41-82 years) and 10 were men (71%). Two had lymphoma risk factors (HIV infection 1; chronic immunosuppression postorgan transplant 1). Most had initial presumptive diagnoses of CNS demyelinating disease and definitive diagnosis of lymphoma was delayed a median of 8 months (range 1-22 months). CNS lymphoma was pathologically confirmed by biopsy (brain 6; spinal cord 4), CSF cytology (3), and autopsy (1). Most patients had multifocal, persistently enhancing lesions on spinal MRI and 8 had involvement of conus medullaris, cauda equina, or both. IV methotrexate was the initial treatment in 9 of 12 (75%) but lymphoma recurred in the majority. Half of the patients were wheelchair-dependent at 10 months and 2-year survival was 36%.

PISCL mimics other causes of myelopathy. Spinal MRI demonstrating multifocal lesions, persistent gadolinium enhancement, and conus medullaris or cauda equina involvement is characteristic. Pathologic confirmation often requires CNS biopsy. Despite chemotherapy, morbidity and mortality is high.