Spontaneous pneumomediastinum and COVID-19 pneumonia: Report of three cases with emphasis on CT imaging

Abstract

Spontaneous pneumomediastinum is a rare complication of coronavirus disease 2019. The published literature consists mainly of case reports and small case series. There are still many questions regarding the pathogenesis, the prognostic significance and the implications on patient management. In our hospital, 3 coronavirus disease 2019 patients developed spontaneous pneumomediastinum: 1 on admission at the emergency department and the other 2 during hospitalization. In this study we describe their clinical course and computed tomography (CT) findings. All of them had severe disease according to the total severity score on admission CT. The management of pneumomediastinum was conservative and follow-up CT showed resolution in all patients. As the correlation between extension of parenchymal lung lesions and development of pneumomediastinum is still under investigation, we highlight the importance of reporting the severity score on chest CT in order to obtain more comparable results between different studies. Furthermore, in this tragic circumstance we also had the opportunity to familiarize ourselves with the otherwise uncommon occurrence of air along the bronchovascular sheaths (Macklin effect) and evaluate the ability of CT to detect it.

Keywords: COVID-19, CT; Macklin effect; Severity score; Spontaneous pneumomediastinum.

Fig. 1

(Patient 1): (A) Chest computed tomography (CT) on admission demonstrating a gas collection anterior to the aortic arch and extensive parenchymal ground glass lesions. (B) CT on admission showing left perihilar Macklin effect. (C) Chest CT on hospital day 6 showing resolution of the pneumomediastinum. More extensive and denser parenchymal lesions are evident in comparison to A. (D) CT on hospital day 13 showing the appearance of fibrotic lesions.

Fig. 2

(Patient 2): (A) Chest computed tomography (CT), lung window, performed on hospital day 10 showing pneumomediastinum (thick black arrow), perihilar and peripheral Macklin effect (thin black arrows). Extensive ground glass lesions with thickened interlobular septa are also evident. (B) Chest CT, lung window, on admission. No sign of pneumomediastinum (thick black arrow) or Macklin effect (thin black arrows) at that time.

Fig. 3

(Patient 3): (A-C) Chest computed tomography (CT) on day 8 showing emphysema mainly extending into the left cervical region (A), pneumomediastinum (B), and pneumopericardium (C). (D) Chest CT on day 8 demonstrating pneumomediastinum (thick arrow) and peripheral Macklin effect. (E) Chest CT on day 13 showing resolution of the Macklin effect (thin arrow) and persistence of small gas bubbles in the anterior mediastinum (thick arrow).