Clinicopathological Study of Mucormycosis in COVID-19: A Cross-sectional Study from a Tertiary Care Centre in North Kerala, India

Abstract

Introduction: Mucormycosis is an angioinvasive disease associated with high morbidity and mortality caused by fungi of the order Mucorales. The rise in the incidence of mucormycosis, along with the surge of Coronavirus Disease- 2019 (COVID-19), justifies reassessment of associated risk factors and the susceptible population. The present study aims to highlight the specific clinicopathological features and risk factors of mucormycosis in COVID-19 patients. Aim: To investigate the histopathological features, key clinical findings in mucormycosis, and the predisposing factors associated with mucormycosis in post-COVID-19 patients. Materials and Methods: This descriptive cross-sectional study was conducted at the Department of Pathology, Government Medical College, Manjeri, Malappuram, Kerala, India, in the Department of Pathology. It included all histopathologically proven Mucormycosis specimens from confirmed COVID-19 positive and post-COVID-19 cases in this Medical College from January 1, 2021, to December 31, 2021, amounting to a total of 30 cases. The type of tissue reaction, fungal hyphae, angioinvasion, necrosis, and fungal co-infections were assessed. Histopathologic analysis was performed using routine Haematoxylin and Eosin (H&E) slides, followed by special stains such as Periodic Acid Schiff (PAS) and Grocott Methenamine Silver (GMS). Data was collected using a proforma, and the clinical details were obtained from the request form received along with the biopsy specimen and case sheets. Age, gender, site of involvement, and risk factors were assessed and subjected to descriptive tabulation and analysis. Results: The mean age was 49.5 years with a male-to-female ratio of 1.30:1. The major risk factors observed in the present study were Diabetes Mellitus (DM) and steroid therapy, 30 all cases (100%), along with others such as chronic kidney disease 2 cases (6.67%) immune disorders, and renal transplantation 1 case each (3.33%). The most commonly involved site was sinuses 27 cases (90.00%). Multiple sinuses were affected in 22 cases (73.33%), with the ethmoid sinus being the most common site 24 cases (80.00%), followed by the maxillary sinus 21 cases (70.00%). The most common reaction pattern observed was acute inflammation 15 cases (50.00%). Angioinvasion was noticed in 19 cases (63.33%) and necrosis was present in 28 cases (93.33%). Co-infection with fungal pathogens was observed in 8 cases (26.67%), with aspergillus being the most common co-infection in all except one of the eight cases. Fungal hyphae were visible on H&E slides in 28 cases (93.33%), while the remaining cases were identified only through special stains (PAS and GMS). Conclusion: Mucormycosis infection is strongly associated with DM and steroid therapy. A more even distribution between males and females was noted, deviating from the male predominance described in most studies. The histopathological appearance of angioinvasion was less frequent compared to most studies, consistent with previous studies on the Indian population. Higher rates of co-infection and the presence of granulomatous inflammation were observed. Further studies are needed to explore the relationship between host immunity, morphological patterns, and their influence on prognosis.