[Immunodeficiency-related intravascular large B-cell lymphoma diagnosed by random skin biopsy manifesting as transverse myelitis].

The patient was a 65-year-old woman with rheumatoid arthritis who was receiving methotrexate. Lumbar disc herniation was suspected due to development of low back pain and bilateral lower limb numbness, and progression of urinary retention and gait disturbances. Laminectomy was performed, but her condition progressed to complete paraplegia. MRI-T2-weighted imaging showed hyperintense lesions in the cervical to thoracic spinal cord. Methylprednisolone (mPSL) pulse therapy and plasmapheresis were performed based on a presumptive diagnosis of transverse myelitis, but produced no clinical improvement. Due to high levels of LDH and soluble interleukin-2 receptor (sIL2R), a random skin biopsy was performed, and intravascular large B-cell lymphoma (IVLBVL) was diagnosed. With R-CHOP, high-dose methotrexate, and intrathecal chemotherapy, LDH, sIL2R, and MRI findings improved, but paraplegia of the lower limbs and urinary retention remained. In patients with unexplained transverse myelitis-like symptoms accompanied by elevated LDH and sIL2R, it is necessary to diagnose IVLBCL at an early stage by random skin biopsy before development of irreversible pathologies such as spinal cord infarction, and to start chemotherapy promptly to improve the neuroprognosis.