Atypical clinical presentation of glioblastoma mimicking autoimmune meningitis in an adult.

Glioblastoma (GBM) is the most malignant type of glial tumor associated with a very unfavorable prognosis. Typical radiological features of GBM include the presence of a tumor with irregular contrast-enhancing margins and central necrosis surrounded by a wide area of vasogenic edema. Here, we presented an atypical clinical presentation of GBM mimicking autoimmune meningitis. A 69-years-old previously healthy male was admitted to the emergency room due to signs of increasing cognitive impairment, weight loss, changes in behavior, difficulty in walking, and prolonged episodes of nausea over the past month. An magnetic resonance imaging (MRI) brain scan revealed hyperintense changes of the periventricular area surrounding brain ventricles in T2 and FLAIR, and post-contrast leptomeningeal enhancement and thickening of meninges involving cerebellar sulci. An additional MRI scan of the cervical spine showed an in-core contrastenhancing lesion on the C7-Th1 level as well as leptomeningeal thickening and post-contrast-enhancement around the spinal cord. Various laboratory tests and two stereotactic biopsies were performed with no essential to diagnosis clinical findings. A couple of months after first hospital admission, the patient died. Post-mortem examination of the brain revealed numerous foci of abnormal tissue inside the subarachnoid space, lateral ventricles, and cerebral aqueduct. Histological examination showed diffuse malignant astroglial neoplasm, and diagnosis of glioblastoma NOS WHO G IV was established. Even though the appearance of usual GBM is widely recognizable, one must bear in mind the possibility of unusual presentation. The presented case highlights the diagnostic difficulties of diffuse glioblastoma with atypical clinical presentation.