A clinico-pathological study of COVID-19 associated rhino-orbital-cerebral mucormycosis

PURPOSE: Known predisposing factors for mucormycosis are neutropenia and diabetes. Though COVID-19 is associated with hyperinflammatory response, a high surge in rhino-orbital-cerebral mucormycosis (ROCM) cases was observed during the second wave. The histopathological features reflect the background pathogenesis. This study analyzes the histopathological features and clinical presentation of COVID-19-associated ROCM. METHODS: In this retrospective observational study, the clinical details of 89 proven ROCM patients treated during May–July 2021 were collected from the case records. Histopathological features were correlated with clinical staging groups and outcomes. The mean neutrophil-to-lymphocyte ratio (NLR) of clinical and outcome groups were compared. RESULTS: The mean age was 54.71 ± 11.03 years, with male patients constituting a majority (78.7%). Uncontrolled diabetes mellitus was noted in 70.8% of patients, and 3.4% had normal range of blood sugar. The mean blood sugar was 298.08 ± 99.51 mg/dL. The mean duration of onset of symptoms of mucormycosis from the diagnosis of COVID-19 was 17.36 ± 7.392 (3–45) days. Poor outcome with disease progression or death occurred in 21.3% of patients. Clinical group II patients (44.9%) with ROCM stages 3c and above had poor outcomes (P = 0.005). Histopathological analysis showed minimal inflammation in 25.8%, neutrophil extracellular trap (NET) in 75.3%, and angio-invasion in 28.1% of patients. Minimal inflammation was associated with clinical group II (P = 0.004) and poor outcome (P = 0.001). Angio-invasion correlated with poor outcome (P = 0.007). Patients with severe clinical group and poor outcome had higher mean NLR with P = 0.017 and P = 0.007, respectively. CONCLUSION: Vision loss and cerebral involvement had poor outcomes. The histopathologic features such as inflammation and angio-invasion along with NLR aid as prognostic indicators in the management of ROCM. The role of NET in the pathogenesis of COVID-19-associated ROCM needs further studies.