A 63-year-old man was admitted with bilateral sensory loss up to thoracic level TH 8, progressive spastic paraparesis of legs, urinary incontinence, and fecal obstipation. Symptoms had begun 3 weeks earlier. Spinal MRI showed a contrast-enhancing mass with perifocal edema in the spinal cord at TH 6–7, and brain MRT was unsuspicious (Fig. 1a). Cerebral spinal fluid (CSF) revealed leukocytosis (19 cells/ll), elevated lactate (4.9 mmol/l), and protein (65.8 mg/dl) without neoplastic cells. Suspecting an autonomic inflammatory disease, steroids were applied, leading only to temporary improvement. Plasma separation brought no improvement. MRI then demonstrated an enlargement of the intramedullary mass with subtotal compression of the spinal cord. A biopsy showed astrocytic cells with GFAP (glial fibrillary acidic protein) and MAP2-positive tumor cells. The Ki67-proliferation index was beyond 5%. Diagnosis of an anaplastic astrocytoma WHO grade III was made. Since gross total resection was impossible, combined radiochemotherapy with temozolomide [1] was undertaken. Symptoms and MRI scans remained stable, but 14 months after the first symptoms, a progressive complete internal and external paresis of the left oculomotor nerve occurred. The other symptoms remained stable. Brain MRI revealed enlargement of the left oculomotor nerve in its prepontine course to the cavernous sinus with contrast enhancement as a sign of cortical infiltration of the adjacent temporomesial parenchyma (Fig. 1b). Spinal MRI showed cervical and thoracic leptomeningeal enhancement (Fig. 1c, d), the primary intramedullary tumor remained stable. CSF revealed elevated lactate (5.3 mmol/l) and lympho-monocytic pleocytosis (14 cells/ll) with atypic cells suspicious for meningeosis neoplastica. A biopsy of the swollen oculomotor nerve showed tumor cells with many mitoses, areas of necrosis, focal GFAP-positive cell accumulation (Online resource 1), and nuclear accumulation of p53 in a few cells. The Ki67 proliferation index was above 30%, therefore the histological evaluation was glioblastoma. Only a few days after the biopsy, the patient developed dysphagia, dysarthria, and dyspnea, which was most likely due to basal infiltration of the leptomeninges, and died within 2 weeks. In summary, the patient presented first with a spinal anaplastic astrocytoma WHO grade III. Later leptomeningeal and cerebral dissemination occurred. Histology revealed a growing malignancy consistent with glioblastoma. This case is of special interest because of the very rare circumstance of a malignant spinal anaplastic astrocytoma spreading to spinal and intracranial leptomeninges and even supratentorial parenchyma. The second biopsy revealed a different—higher—grade than before, therefore a multifocal glioma cannot be ruled out completely, but Electronic supplementary material The online version of this article (doi:10.1007/s00415-011-6253-0) contains supplementary material, which is available to authorized users.