Histopathological Predictors of Severity of Fungal Infection in Cases of Post-COVID-19 Outbreak of Rhino-Orbital-Cerebral Mucormycosis

Abstract Background: A spike in rhino-orbital-cerebral mucormycosis (ROCM) cases was ascertained in the aftermath of the COVID-19 pandemic in South Asia. Materials and Methods: In this study, the histopathology slides of 214 samples from 162 patients diagnosed with ROCM (received throughout the post-COVID-19 outbreak) were retrieved. The histopathologic features were evaluated as per predetermined criteria and correlated with clinical stage, mortality, and other details. Results: Out of 162 patients, 25 patients (15.4%) succumbed to the disease while 137 (85.4%) recovered. A lower fungal load conferred a statistically significant better chance of survival for the patients. The presence of vessel thrombosis, higher fungal load, and absence of giant cells were found to have a significant correlation with higher clinical stage of the fungal infection. Following histopathologic features were found to have no statistically significant correlation with either the stage of the disease or mortality-angioinvasion, perineural invasion, lymphoplasmacytic infiltration, foamy histiocytes, grade of neutrophilic infiltration, granulomatous reaction, presence of oxalate crystals, and grade of coagulative necrosis. Conclusion: In the post-COVID-19 setting, higher fungal load, vessel wall thrombosis, and absence of giant cell reaction correlate with higher clinical stage of the disease.