[A case of primary intramedullary spinal cord lymphoma diagnosed by spinal cord biopsy of long spinal cord lesions showing persistent gadolinium contrast enhancement].

An 82-year-old man presented with subacute bilateral lower limb paralysis, deep sensory disturbance, and vesico-rectal disturbance. MRI of the spinal cord revealed a large gray matter-dominant lesion extending from the medulla oblongata to the lower thoracic spinal cord. The patient was treated with steroid-pulse therapy for myelitis, but without symptomatic improvement. A spinal cord biopsy was performed for treatment-resistant myelopathy, and histopathology revealed a diffuse large B-cell lymphoma, that was diagnosed as a primary intramedullary spinal cord lymphoma because systemic examination didn't show any other findings suggestive of malignant lymphoma. A spinal cord biopsy is necessary for the definitive diagnosis of this disease, but in the case of poor response to treatment and a progressive course, intramedullary malignant lymphoma should be considered if there is a persistent elevation of CSF IL-10 or a prolonged contrast effect.