The spectrum of radiological findings of rhino orbital cerebral mucormycosis with endoscopic and histopathological features in patients with COVID 19: A descriptive study

Abstract

Background: There had been an increasing incidence of mucormycosis during the COVID-19 pandemic. Aim: This study evaluates the pattern of radiological imaging, endoscopic and histopathological features of rhino-orbital cerebral mucormycosis in patients with COVID-19 infection. Materials and Methods: The study included 31 patients with culture/biopsy-proven mucormycosis and COVID-19 infection from November 1, 2020, to December 31, 2021, in a single tertiary care centre. This study was approved by institutional ethics committee. Computed tomography (CT)/magnetic resonance imaging (MRI) images, endoscopic, and histopathological findings were retrospectively analyzed to look for the extent and pattern of disease. Statistical analysis was performed through descriptive statistics. Results: The imaging spectrum showed paranasal sinus involvement (n = 31; 100%), nasal involvement (n = 14; 45.16%), oral and palatal involvement (n = 6; 19.3%), deep neck/face space involvement (n = 25; 80.6%), orbital involvement (n = 20; 64.5%), vascular complications (n = 9; 29%), skull base involvement (n = 12; 38.7%), and cerebral involvement (n = 10; 32.2%). Endoscopy showed black necrotic tissue and slough mostly affecting middle turbinate, maxillary, and sphenoid sinuses. CT showed 100% sensitivity and specificity for the detection of sinonasal osseous erosion. Histopathology examination revealed mucormycosis as broad aseptate, predominantly 90° branching hyphae with macrophage and neutrophilic infiltration in 93.5%, granuloma in 61.3%, cavity formation in 48.4%, and angioinvasion in 77.4%. Diabetes mellitus was the predominant coexisting morbidity for mucormycosis. The mean time interval between COVID-19 diagnosis and mucormycosis was 18 days. Conclusion: CT revealed hyperdense contents within sinuses with osseous erosion; while MRI showed T2 hypointense, heterogeneously enhancing lesions with adjacent structural infiltration, orbital inflammation, cavernous sinus and internal carotid artery thrombosis, and intracranial complications such as infarct, hemorrhage, meningitis, and abscess. Neutrophilic infiltration and angioinvasion were predominant histopathological characteristics while necrosis with eschar formation was demonstrated through endoscopy.