Histopathological changes in lungs of patients with fatal COVID 19 infection: A series of 15 cases.

Introduction: The predominant pathology noted in the lungs of patients dying of COVID-19 is reported to be diffuse alveolar damage (DAD). Other studies have identified microthrombi to be a prominent finding of lung injury in patients affected by COVID-19. We describe the lung histopathological findings in fifteen cases of COVID-19 who died from the disease with the aim of reporting the microscopic changes in the lungs of patients dying from this disease. Materials and Methods: Lung tissues from fifteen consecutive autopsy cases of COVID-19 were studied for gross and microscopic features. The case history of the deaths was noted, and the information was analyzed. The lung damage seen was graded on a semiquantitative scale on the basis of the percentage of tissue involved. Results: Gross examination of the lungs showed multiple foci of consolidation mainly in the lower lobes of the lungs as the most commonly encountered finding. The other significant pattern was congested and edematous lungs with areas of consolidation. Microscopic assessment of lung sections showed 8 out of the 15 cases showing changes of the exudative phase of diffuse alveolar damage, whereas two cases were in the proliferative phase. Hyaline membranes were one of the common findings along with intra-alveolar edema and interstitial edema. Four cases showed changes in organizing phase. Other findings were microthrombi formation, fungal abscesses, dilated and collapsed alveoli, intra-alveolar hemorrhage, and acute neutrophilic pneumonia. Conclusion: DADand interstitial pneumonitis were the most striking features in our autopsy study. Features of different phases of diffuse alveolar damage were seen to coexist in the same patient indicating the temporal heterogeneity of the ongoing lung injury in these patients.

Dengue virus serotypes and genotypic characterization from northeast India.

Dengue is a rapidly spreading acute arboviral infection transmitted through a human and Aedes mosquito cycle. Though northeast region of India has been experiencing dengue outbreaks regularly for over a decade, reports on genetic characterization of the virus from this region are limited. The present study was undertaken to detect the genotype and genetic composition of circulating dengue virus (DENV) in this region. Blood samples were collected from 918 suspected dengue patients of five northeast Indian states. Serological investigations, viz, nonstructural 1 (NS1) enzyme-linked immunosorbent assay (ELISA), immunoglobulin M (IgM) ELISA, and immunoglobulin G (IgG) ELISA were performed followed by molecular detection. Sequence analysis and phylogenetic tree construction based on capsid-premembrane (C-prM) gene junction was done by BioEdit and MEGA6 software, respectively. Serological detection showed 35.34% NS1 and 18.12% IgM positivity. Secondary infection was observed in 24.53%. All four serotypes were detected. Phylogenetic analysis demonstrated circulation of genotype III of DENV-1, genotype IV of DENV-2, and genotype III of DENV-3. Sequences from this region form distinct clades in the phylogenetic tree. Characterization of the C-prM gene junction reveals divergence among the DENV strains. As genetic variation within the DENV is known to be associated with diverse clinical outcomes, information regarding the genetic composition of circulating virus could be beneficial in designing an effective intervention strategy.

Cytodiagnosis of mucosal malignant melanoma of nasal cavity: A case report with review of literature.

Sinonasal malignant melanoma is of unusual occurrence. Common sites for melanomas are head, neck region, and the lower extremities as they are exposed to sunlight, which is one of the predisposing factors. We report a case of primary mucosal malignant melanoma of the nasal cavity in a 68-year-old male for its rare occurrence. The primary knowledge of its existence and evaluation of its cytological features are important for a correct preoperative cytological diagnosis and thereby clinical implications for appropriate therapeutic intervention. The cytological features when evaluated along with clinical, histopathological and immunohistochemical features are sufficiently diagnostic. The rarity of its occurrence warrants its mention.