Morphological and tissue-based molecular characterization of oral lesions in patients with COVID-19: An update of a living systematic review

Objective

This is the update of the previously published living systematic review that integrated the morphological and tissue-based molecular characterization of oral lesions occurring in individuals infected with COVID-19 (OLICs).

Methods

This study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Web of Science, Scopus, Ovid, Embase, and LILACS were searched to identify reports on OLICs with morphological and/or tissue-based molecular data.

Results

Six studies, reporting nineteen cases of OLICs, were included. Of the patients, 73.7 % were males with a mean age of 54.8 (± 18.8) years. The most commonly observed clinical presentation was ulcers (42.9 %), primarily in the palate (52 %). Histopathologically, the most frequently reported features in the mesenchymal layer were thrombi/microvascular thrombosis (36.6 %), inflammation (24.4 %), and hemorrhage (14.7 %). Immunohistochemistry for SARS-CoV-2 or Spike Protein was conducted in 15 cases, revealing 86.7 % positivity. In one study, RT-PCR yielded a negative result, which was further confirmed by negative immunohistochemistry.

Conclusion

The occurrence of thrombotic events associated with the presence of the spike protein could explain the etiopathogenesis of some cases of OLICs, probably also associated with other etiological factors.