Neuropathology of the temporal lobe.

Neuropathological examination of the temporal lobe provides a better understanding and management of a wide spectrum of diseases. We focused on inflammatory diseases, epilepsy, and neurodegenerative diseases, and highlighted how the temporal lobe is particularly involved in those conditions. Although all these diseases are not specific or restricted to the temporal lobe, the temporal lobe is a key structure to understand their pathophysiology. The main histological lesions, immunohistochemical markers, and molecular alterations relevant for the neuropathological diagnostic reasoning are presented in relation to epidemiology, clinical presentation, and radiological findings. The inflammatory diseases section addressed infectious encephalitides and auto-immune encephalitides. The epilepsy section addressed (i) susceptibility of the temporal lobe to epileptogenesis, (ii) epilepsy-associated hippocampal sclerosis, (iii) malformations of cortical development, (iv) changes secondary to epilepsy, (v) long-term epilepsy-associated tumors, (vi) vascular malformations, and (vii) the absence of histological lesion in some epilepsy surgery samples. The neurodegenerative diseases section addressed (i) Alzheimer's disease, (ii) the spectrum of frontotemporal lobar degeneration, (iii) limbic-predominant age-related TDP-43 encephalopathy, and (iv) α-synucleinopathies. Finally, inflammatory diseases, epilepsy, and neurodegenerative diseases are considered as interdependent as some pathophysiological processes cross the boundaries of this classification.

COVID-19-Associated Encephalitis Mimicking Glial Tumor.

BACKGROUND: Reports on neurologic manifestations of coronavirus disease 2019 (COVID-19) have attracted broad attention. We present an unusual case of COVID-19-associated encephalitis mimicking a glial tumor. CASE DESCRIPTION: A 35-year-old woman presented with headache and seizures. T2 fluid-attenuated inverse recovery imaging showed hyperintensities in the left temporal lobe. Magnetic resonance spectroscopy showed an elevated choline peak. Imaging findings were suggestive of high-grade glioma. Antiepileptic medication failed to achieve seizure control. A left anterior temporal lobectomy was performed. The patient had no postoperative deficits, and her symptoms completely improved. Histologic examination revealed encephalitis. Postoperatively, our patient tested positive for COVID-19. CONCLUSIONS: Our case raises awareness of neurologic manifestations of the disease and their potential to mimic glial tumors. For prompt diagnosis and prevention of transmission, clinicians should consider COVID-19 in patients with similar presentation.