Brainstem gliomas in adults are a rare and heterogeneous group of brain tumours, which account for less than 2% of all adult gliomas and usually involve the pons (60-63%). The medulla oblongata and the midbrain are the least common locations of brainstem gliomas (25% and 12-15%, respectively). Survival and overall prognosis depend on the underlying pathology and pathological tumour grade. The authors present a female patient with medulla oblongata rapidly growing brainstem glioma (documented in a series of brain MRI examinations), which resulted in quick progression of neurological symptoms with cardiopulmonary insufficiency and death. The rapid growth of this lethal lesion and clinical deterioration made it impossible to perform stereotactic biopsy and implement optimal oncological treatment. Neuropathological brain and spinal cord postmortem examination revealed glioblastoma IDH-wildtype CNS WHO G4.