[Case of 55-year-old female with primary central nervous system lymphoma, presenting with brain and eye lesions and long-term relapsing/remitting course].

We report the case of a 55-year-old immunocompetent female with primary central nervous system lymphoma (PCNSL). Seven years previously, the patient presented with left facial dysesthesia, and a right thalamus lesion was revealed by brain MRI. Both her dysesthesia and the lesion disappeared spontaneously in six months. One year previously, she noted motor disturbance of the right limbs, and brain MRI revealed lesions in the bilateral basal ganglia and the left internal capsule which gradually increased in size. She was admitted to our hospital owing to the brain MRI findings of a white matter lesion in the left occipital lobe and bilateral optic neuritis. Previously, she had experienced two episodes of steroid-responsive uveitis in her left eye. An inflammatory disease such as multiple sclerosis was initially suspected because of the relapsing/remitting clinical course with a long time interval. Treatment with corticosteroids improved her clinical symptoms and decreased the size of the lesions, but the brain lesions and bilateral optic neuritis recurred within one month. At that time, the β2 microglobulin level in the cerebrospinal fluid was high and the left occipital lobe lesions showed increased 18F-fluoro-deoxyglucose uptake in positron emission tomography and decreased Cho/NAA ratio in 1H-MR spectroscopy. These findings suggested PCNSL. A brain biopsy confirmed the presence of diffuse large B cell lymphoma. Both uveitis and optic neuritis were considered to be caused by intraocular lymphoma associated with PCNSL. Although patients with PCNSL may experience temporary spontaneous remission, our present case suggests that the time interval from remission to relapse can be much longer than generally expected. We suggest that it is necessary to consider PCNSL and perform a brain biopsy on patients presenting with atypical clinical manifestations of an inflammatory disease, even in cases with a long clinical course.