RESUMEN
Primary lymphoma of the central nervous system is a rare disease, occurring spontaneously and/or in conjunction with immunosuppressive state. Its incidence is increasing according to the increment of organ transplantation and AIDS. Recently we experienced a case of primary lymphoma occurred in central nervous system after renal transplantation in a 58-year-old women who had complained of persistent headache and left hemiparesis. CT scan of the brain showed two hyperdense mass lesions in right frontal and right basal ganglia areas. Immunohistochemical stain of the excised mass lesion revealed that tumor cells were derived from B cells. The patient was treated with discontinuance of immunosuppressive drug and irradiation, but expired due to pneumonia.