[A case of methotrexate-associated diffuse large B-cell lymphoma with splenial lesions of the corpus callosum on brain MRI after complete remission with chemotherapy].

An 86-year-old woman in a wheelchair was accompanied by her husband and son as she visited our outpatient clinic due to disturbed consciousness and fever. Twenty-seven years earlier, she had been diagnosed with rheumatoid arthritis and had been treated with methotrexate (MTX) and low-dose prednisolone (PSL). She stopped taking MTX four years previously when she was diagnosed with diffuse large B cell lymphoma of the paranasal sinus.