Radiographic analysis provides evidence for the etiology of pulmonary cysts in COVID-19

Imaging of patients with COVID-19 has provided unique insights into the pathophysiology of the infection. Cysts are a rare manifestation of the disease in the lung. The aim of this research was to compare COVID-19-positive patients with cysts on CT to patients without cysts and propose a mechanism for cyst formation in this patient population based on radiographic observations.Our HIPAA-compliant IRB-approved research project involved a retrospective review of 219 chest CT scans identified in COVID-19-positive inpatients and emergency room patients at Columbia University Irving Medical Center from February 27, 2020 to July 17, 2020. A thoracic radiologist with over 20 years of experience reviewed the images on lung window settings and identified the presence of cysts, their distribution (central or pleural based), and if there was an accompanying pneumothorax. The extent of consolidation of the entire lung on a scale of 0–16 and the presence of fibrosis were also documented.Cysts were identified in 10 of the 219 patients. CT scans with cysts were obtained on average on day 57 of symptoms (range 16–115 days) compared to CT scans of those without cysts that were obtained on average on day 19 (range 0–89 days). The distribution of cysts was heterogeneous; six patients had multiple cysts while four were isolated. Seven cysts were peripheral in distribution while three were central. Two patients with cysts developed a subsequent pneumothorax. Fifty percent of those with cysts had been intubated.Patients with COVID-19 develop cystic lung lesions for at least two reasons; pleural-based lesions are more likely areas of infarction and central lesions with surrounding ground glass are more likely related to infection and/or mechanical ventilation.