Case of primary diffuse leptomeningeal gliomatosis. Yamasaki Kouji,Yokogami Kiyotaka,Ohta Hajime,Yamashita Shinji,Uehara Hisao,Sato Yuichiro,Takeshima Hideo Brain tumor pathology Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare and fatal disease characterized by diffuse infiltration of the leptomeninges by neoplastic glial cells without evidence of tumor in the brain parenchyma or spinal cord. We report a 60-year-old man with PDLG. He suffered transient right hemiparesis and generalized seizures. MRI showed diffuse leptomeningeal thickening and enhancement throughout the brain and spinal cord without any intraaxial involvement. Biopsy resulted in a diagnosis of glioblastoma with methylated MGMT promoter and wild-type IDH1. He underwent craniospinal radiotherapy and temozolomide treatment but despite concomitant adjuvant therapy he died 8 months after initial presentation. 10.1007/s10014-014-0176-2