A young farmer (21-year-old male) presented with parietooccipital headache and lower back pain. He had no further neurological deficits. A year previously, he had presented with an epileptic seizure, and cranial MRI had shown a frontal tumor, typical for a low-grade astrocytoma. A biopsy had been indicated, but the patient had refused further examinations at that time.
At this presentation, cerebrospinal fluid (CSF) analysis revealed a pleocytosis (49/muL) with massive elevation of protein (>4 g/L) and lactate (9.6 mmol/L) levels. A tuberculous meningitis was suspected and tuberculostatic therapy initiated. MRI showed contrast enhancement in the perimedullary, cerebellar and cauda equina regions. Granulomatous inflammation, possibly due to tuberculosis or carcinomatosis, was presumed. All further diagnostics to exclude bacterial, viral, fungal or autoimmune disease, as well as a CSF cytology with FACS (fluorescence-activated cell sorting) analysis, showed no pathological results.
The patient developed a progressive brain stem syndrome with fluctuating left arm palsy and delirium. A biopsy of the tumor and the leptomeninx revealed edematous brain tissue with small fresh hemorrhages and slight, most likely reactive, astrogliosis with focal chronic inflammatory changes in the overlying leptomeninx. There was no immunohistochemical detection of an isocitrate dehydrogenase 1 (IDH1) mutation. It was only on the third biopsy of brain tissue that leptomeningeal cell proliferation with singular mitoses suspicious for a leptomeningeal neoplastic process was revealed.
The condition of the patient worsened, and he was subsequently resuscitated and intubated as a result of cardiopulmonary insufficiency and cardiac arrest. The patient died 3 months after admission.
The autopsy revealed atypical astrocytic differentiated cell clusters with moderate cell and nuclear polymorphism and with a low proliferation rate in the region of the suspected frontal tumor, corresponding to a low-level malignant diffuse astrocytoma (WHO grade II). A diffuse, malignant, astrocytically differentiated leptomeningeal glioma was found in the overlying meninges, compatible with a primary leptomeningeal glioblastoma of a diffuse type (WHO grade IV, IDH wild type) with tumor infiltration of the cerebral parenchyma and the cerebellar cortex (Fig. 1).