Cerebral venous sinus thrombosis associated with COVID-19: an autopsy case report.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. COVID-19 has been reported to increase the propensity for systemic hypercoagulability and thromboembolism disorders such as cerebral venous sinus thrombosis (CVST). A 66-year-old woman was found dead at her home. She had symptoms of fever, dizziness, and malaise 2 weeks prior to her death. However, her fever declined 3 days before death. Postmortem computed tomography conducted before the autopsy suggested CVST. On autopsy, a massive thrombus was observed from the cortical veins to the superior sagittal sinus and transverse sinus accompanied by a small infarction region in the left parietal region. Although the rapid antigen test was negative, the reverse transcription-quantitative polymerase chain reaction test was positive for SARS-CoV-2, with a cycle threshold (Ct) value of 38.9. The serum C-reactive protein level was 0.532 mg/dL. COVID-19 was the only risk factor for CVST, and no other cause of death was determined. Therefore, the cause of death was determined as acute intracranial hypertension due to CVST associated with COVID-19. The patient died after the symptoms improved, the Ct value of RT-qPCR was 38.9, and the serum C-reactive protein level decreased. Therefore, CVST might have occurred in the convalescent phase of COVID-19 infection.

Spontaneous Improvement of Visual Acuity in a 13-Year-Old Boy with Neuromyelitis Optica Spectrum Disorder.

Ophthalmic and MRI evaluations of a 13-year-old boy who reported loss of visual acuity in his right eye demonstrated the presence of unilateral optic neuritis. After serological tests showed positivity for anti-aquaporin 4 antibody, he was diagnosed with neuromyelitis optica spectrum disorder. Encephalopathy and myelitis were not observed. Since his unilateral optic neuritis was considered to reflect mild disease activity, only follow-up observations were performed. Visual acuity and central scotoma improved 1 week after the first examination. In the absence of any specific treatments, good visual acuity has remained for 20 months, with no relapse of optic neuritis.

Mucinous carcinoma of the gallbladder with signet ring cells.

Most gallbladder carcinomas are adenocarcinomas, of which mucinous carcinoma (MC) is a rare pathologic subtype. Signet ring cells are seldom found in MCs. We report an extremely rare case of gallbladder MC with signet ring cells. This is the first radiological case report about this rare type of histologic entity with detailed discussion of imaging findings in the English literature. In addition to the features of MC, linitis plastica-like invasion, which is the key feature of signet ring cells, was confirmed by both imaging and histopathologic analysis. Furthermore, radiologists should know how the imaging findings of MC differ from those of other major subtypes of adenocarcinoma, as there is a risk of delays in diagnosis and underestimation of tumor spread.