COVID-19: a Disease with a Potpourri of Histopathologic Findings-a Literature Review and Comparison to the Closely Related SARS and MERS

Risk of New-Onset Liver Injuries Due to COVID-19 in Preexisting Hepatic Conditions-Review of the Literature

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacted the world and caused the 2019 coronavirus disease (COVID-19) pandemic. The clinical manifestations of the virus can vary from patient to patient, depending on their respective immune system and comorbidities. SARS-CoV-2 can affect patients through two mechanisms: directly by targeting specific receptors or by systemic mechanisms. We reviewed data in the latest literature in order to discuss and determine the risk of new-onset liver injuries due to COVID-19 in preexisting hepatic conditions. The particular expression of angiotensin-converting enzyme 2 (ACE2) receptors is an additional risk factor for patients with liver disease. COVID-19 causes more severe forms in patients with non-alcoholic fatty liver disease (NAFLD), increases the risk of cirrhosis decompensation, and doubles the mortality for these patients. The coinfection SARS-CoV-2-viral hepatitis B or C might have different outcomes depending on the stage of the liver disease. Furthermore, the immunosuppressant treatment administered for COVID-19 might reactivate the hepatic virus. The high affinity of SARS-CoV-2 spike proteins for cholangiocytes results in a particular type of secondary sclerosing cholangitis. The impact of COVID-19 infection on chronic liver disease patients is significant, especially in cirrhosis, influencing the prognosis and outcome of these patients.

Mechanisms of COVID-19-induced cerebellitis

The COVID-19 pandemic caused by SARS-CoV2 has raised several important health concerns, not least increased mortality and morbidity. SARS-CoV2 can infect the central nervous system via hematogenous or transneuronal routes, acting through different receptors including ACE2, DPP4, and neuropilin 1 and cause several issues, including the focus here, cerebellitis. The cerebellum is an essential part of the CNS located adjacent to the brainstem with a complex micro and macroscopic structure. The cerebellum plays several physiological roles, such as coordination, cognition, and executive functioning. Damage to the cerebellum can lead to incoordination and ataxia. In our narrative review, we searched different databases from 2021 to 2022 with the keywords cerebellum and COVID-19; 247 studies were identified and reviewed, focusing on clinical studies and excluding non-clinical studies; 56 studies were finally included for analysis. SARS-CoV2 infection of the cerebellum can be seen to be assessed through many methods such as MRI, PET, CT, postmortem studies, and histological findings. These methodological studies have demonstrated that cerebellar infection with COVID-19 can bring about several sequelae: thrombosis, microbleed, hemorrhage, stroke, autoantibody production, ataxia, and widespread inflammation in the cerebellum. Such central effects are likely to exacerbate the known multiorgan effects of SARS-CoV2 and should also be considered as part of disease prognosis.

Atypical follicular hyperplasia with light chain-restricted germinal centers after COVID-19 booster: a diagnostic pitfall

There has been a surge in COVID-19 vaccine-associated lymphadenopathy (LAD), including after the booster dose of vaccine. This can create diagnostic dilemmas in oncology patients as the relatively sudden LAD can mimic metastasis or cancer recurrence, at a risk of leading to additional but unnecessary anti-neoplastic therapy. Here we report the histopathologic features in a case of persistent LAD occurring in a patient with history of breast invasive ductal carcinoma which followed a COVID-19 vaccine booster. A needle core and then excisional biopsy showed atypical follicular hyperplasia with features that histologically and phenotypically could mimic follicular lymphoma, but the findings were ultimately interpreted to be reactive in nature and related temporally to COVID-19 vaccine. To our knowledge, this is the first case of an atypical lymphoproliferative lesion with features potentially mimicking lymphoma associated with COVID-19 vaccine.