[A case of intracranial primary leptomeningeal lymphoma].

Primary leptomeningeal lymphoma(PLML)is a neoplastic meningitis of lymphomatous origin without parenchymal central nervous system(CNS)disease or a systemic tumor. We report a case of PLML that presented with epileptic seizure, and review relevant literature. A 27-year-old man was brought to the emergency department with an epileptic seizure. Two months later, he was again brought to the emergency department with an epileptic seizure. MRI showed enhanced lesions on the surface of the right cerebellar hemisphere, right parietal sulci, and interhemispheric surface of the frontal lobes. We performed an open biopsy and diagnosed the patient with diffuse large B-cell lymphoma of the leptomeninges on the basis of histological findings. The patient was initially treated with chemotherapy including high-dose methotrexate(MTX). Because remission was not achieved by chemotherapy, the patient was treated with whole-brain radiation therapy. After onset, the patient survived for 2 years without recurrence. PLML is a particularly rare type of primary CNS lymphoma. The outcome of PLML, compared with general primary CNS lymphoma, is reported to be very poor because chemotherapy including MTX is ineffective.