Correlation of Diagnostic Yield with Laboratory Parameters and Histopathological Examination in Clinically Suspected Cases of Mucormycosis in Post-COVID-19 Patients: A SingleCenter Study in Ahmedabad, India.

Background and objectives: Mucormycosis is a complication in post-coronavirus disease 2019 (COVID-19) patients in India. This study was done to evaluate the prognostic value of clinical, histopathologic findings, microbiological features, and biochemical parameters such as D-dimer, lactate dehydrogenase, and serum ferritin in post- COVID-19-patients with rhino-orbital mucormycosis. Methods: This retrospective observational study was carried out on biopsies taken from 50 post-COVID-19 patients suspected of mucormycosis. The biopsy specimens were processed and stained with hematoxylin and eosin, periodic acid– schiff, and Wright-Giemsa. In addition, 10–20% potassium hydroxide wet mount and culture on sabouraud dextrose agar were performed to detect Mucor. The biochemical parameters were measured using ARCHITECT ci8200 chemistry analyzer. Results: Overall, 30 cases (60%) were positive for fungal elements, and growth of Mucor spp. was found in 28 cases (56%). In histopathology, 70% of cases (n=35) showed broad, aseptate, ribbon-like hyphae with wide-angled branching diagnostic of mucormycosis. There seemed to be a site-wise overlap between the nasal/maxillary sinus and rhinoorbital/rhino-cerebral variety. There was no difference between the patients in terms of gender. The most common risk factor was diabetes mellitus (observed in 80% of cases). In patients with invasive mucormycosis, inflammatory biomarkers such as serum ferritin, serum lactate dehydrogenase, C-reactive protein, and Ddimer were greater than the normal range, whereas procalcitonin was within the reference range. Conclusion: It can be concluded that raised metabolic markers, direct 10% KOH examination and histological features including angioinvasion as well as rhino-orbital and cerebral extension might assist doctors in diagnosis, progression, and survival rate. [ABSTRACT FROM AUTHOR]