In and around the pineal gland: a neuroimaging review.

Lesions arising in or around the pineal gland comprise a heterogeneous group of pathologies ranging from benign non-neoplastic cysts to highly malignant neoplasms. Pineal cysts are frequently encountered as an incidental finding in daily radiology practice but there is no universal agreement on the criteria for, frequency of, and duration of follow-up imaging. Solid pineal neoplasms pose a diagnostic challenge owing to considerable overlap in their imaging characteristics, although a combination of radiological appearances, clinical findings, and tumour markers allows for narrowing of the differential diagnosis. In this review, we describe the radiological anatomy of the pineal region, clinical symptoms, imaging appearances, and differential diagnosis of lesions arising in this area, and highlight the clinical management of these conditions.

Neuropathological findings in two patients with fatal COVID-19.

AIMS: To describe the neuropathological findings in two cases of fatal Coronavirus Disease 2019 (COVID-19) with neurological decline. METHODS: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection was confirmed in both patients by reverse transcription polymerase chain reaction (RT-PCR) from nasopharyngeal swabs antemortem. Coronial autopsies were performed on both patients and histological sampling of the brain was undertaken with a variety of histochemical and immunohistochemical stains. RNAscope® in situ hybridization (ISH) using the V-nCoV2019-S probe and RT-PCR SARS-CoV-2 ribonucleic acid (RNA) was performed in paraffin-embedded brain tissue sampled from areas of pathology. RESULTS: Case 1 demonstrated severe multifocal cortical infarction with extensive perivascular calcification and numerous megakaryocytes, consistent with a severe multi-territorial cerebral vascular injury. There was associated cerebral thrombotic microangiopathy. Case 2 demonstrated a brainstem encephalitis centred on the dorsal medulla and a subacute regional infarct involving the cerebellar cortex. In both cases, ISH and RT-PCR for SARS-CoV-2 RNA were negative in tissue sampled from the area of pathology. CONCLUSIONS: Our case series adds calcifying cerebral cortical infarction with associated megakaryocytes and brainstem encephalitis to the spectrum of neuropathological findings that may contribute to the neurological decompensation seen in some COVID-19 patients. Viral RNA was not detected in post-mortem brain tissue, suggesting that these pathologies may not be a direct consequence of viral neuroinvasion and may represent para-infectious phenomena, relating to the systemic hyperinflammatory and hypercoagulable syndromes that both patients suffered.