Evaluation of Pathological Findings of COVID-19 by Minimally Invasive Autopsies: A Single Tertiary Care Center Experience from India.

The 2019 novel coronavirus (2019-nCoV) has spread across the globe with more than 6 lakh deaths. Clinical autopsies are important to understand the pathobiology of the disease.  Autopsy techniques have been modified to be minimally invasive autopsies in all COVID-19 positive cases, and tissue biopsies were sampled from lungs, liver, and bone marrow within an hour after death. Detailed histological analysis was performed in the sampled tissues, along with immunohistochemistry. Patients' clinical records were collected.  Descriptive statistics were used to summarize data.  Of the 21 cases studied, 76.2% patients were ≥ 60 years of age, 80.9% were males, and 85.7% had co-morbidities. Histopathological analysis revealed diffuse alveolar damage (including exudative and organizing phase) in 88.9% cases. Microthrombi were seen in 44.4% cases. Additional findings include viral cytopathic changes, metaplastic change in the epithelium, intra-alveolar hemorrhage, and pulmonary edema. Liver showed centrizonal congestion with hepatocytic loss, lobular inflammation, steatosis, Kupffer cell hypertrophy, and sinusoidal neutrophilic infiltration, while significant portal infiltrate and cholestasis were absent to minimal. Bone marrow revealed hemophagocytosis in 60% cases.  Incorporation of minimally invasive autopsies provides an effective method to study the pathological findings in COVID-19 deaths in resource-constrained settings. Presence of pulmonary microthrombi in a significant number of cases supports the vascular events, apart from the characteristic diffuse alveolar damage, as an important pathogenic mechanism for lung injury in COVID-19 infections. Histopathological findings in the liver and bone marrow suggest indirect insult to these organs, related to circulatory and/or hyperinflammatory response to viral infections.