[Primary central nervous system post-transplant lymphoproliferative disorder with few specific abnormal findings observed on MRI and in the cerebrospinal fluid].

A 60-year-old woman, who had a kidney transplant 16 years ago, was admitted to our hospital owing to cognitive decline and gait disturbances. She developed ataxia, consciousness disturbances, and myoclonus, and died two years after the onset of symptoms. No specific findings were observed on MRI or in the cerebrospinal fluid and blood analyses. The patient was diagnosed with post-transplant lymphoproliferative disorder (PTLD) based on the results of the autopsy. Pathological findings revealed proliferating monoclonal B cells in the perivascular space that was confined to the central nervous system. PTLD is a serious complication of transplantation. Furthermore, PTLD of the central nervous system usually presents as nodular lesions on MRI. When neurological symptoms appear after transplantation, it is necessary to consider PTLD as a differential diagnosis even if abnormal findings cannot be pointed out on MRI.