Comparison of Chest CT Manifestations of Coronavirus Disease 2019 (COVID-19) and Pneumonia Associated with Lymphoma

Objective: To retrospectively compare the clinical features and chest computed tomography (CT) characteristics of coronavirus disease 2019 (COVID-19) and pneumonia in lymphoma patients. Materials and Methods: Ten lymphoma patients with pneumonia and 12 patients with COVID-19 infections were enrolled from January 15 to March 14, 2020. The clinical features were recorded. All pulmonary lesions on chest CT were assessed for location, shape, density and diffusion degree. Other typical CT features were also evaluated. Results: The most commonly observed patchy lesions were ground-glass opacities (GGOs) and mixed GGOs in both groups. Regarding the diffusion degree, 82% (92/112) of the lesions in the COVID-19 group were relatively limited, while 69% (52/75) of those in the lymphoma group were diffuse (p < 0.001). The proportions of interlobular septal thickening, vascular thickening, pleural involvement and fibrous stripes observed in the lymphoma cases were statistically compatible with those observed in the COVID-19 cases (p > 0.05). Air bronchograms were observed more frequently in COVID-19 patients (45%, 50/112) than in lymphoma patients with pneumonia (5%, 4/75) (p < 0.001). Halo sign (6%) and reversed halo sign (1%) were observed in several COVID-19 patients but not in lymphoma-associated pneumonia patients. Conclusion: Both lymphoma-associated pneumonia and COVID-19 generally manifested as patchy GGOs and mixed GGOs in more than one lobe. Compared to COVID-19, lymphoma-associated pneumonia tended to be relatively diffuse, with fewer air bronchograms, and no halo or reversed halo signs observed on chest CT.