Liver Pathology and SARS-CoV-2 Detection in Formalin-Fixed Tissue of Patients With COVID-19

The novel coronavirus, severe acute respiratory syndrome coronavirus 2, causing coronavirus disease 2019 (COVID-19) remains a global health threat and a significant source of human morbidity and mortality. While the virus primarily induces lung injury, it also has been reported to cause hepatic sequelae.

We aimed to detect the virus in formalin-fixed tissue blocks and document the liver injury patterns in patients with COVID-19 compared with a control group.

We were able to detect viral RNA in the bronchioalveolar cell blocks (12/12, 100%) and formalin-fixed, paraffin-embedded tissue of the lung (8/8, 100%) and liver (4/9, 44%) of patients with COVID-19. Although the peak values of the main liver enzymes and bilirubin were higher in the patients with COVID-19 compared with the control group, the differences were not significant. The main histologic findings were minimal to focal mild portal tract chronic inflammation (7/8, 88%, P < .05) and mild focal lobular activity (6/8, 75%, P = .06).

We found that most patients who died of COVID-19 had evidence of mild focal hepatitis clinically and histologically; however, the virus was detected in less than half of the cases.