17 January 2026
: Case report 
Red Complex Bacteria as a Hidden Cause of Chronic Lung Abscess: A Case Report
Rare disease
Hong Chang ABCDEF 1, Xiaohua Qin ABCDEF 2,3*DOI: 10.12659/AJCR.949102
Am J Case Rep 2026; 27:e949102
Figure 1 CT scans of the patient’s chest during hospitalization and the patient’s periodontal condition. (A) Chest CT scan on admission showing patchy shadowing with a thick-walled small cavity in the right upper lobe (arrow). The consolidated lesion contains minimal hypodense liquefactive changes. (B) Clinical photo of the patient’s periodontal condition showing dental plaque (arrow), gingival recession (arrow), and alveolar bone resorption, consistent with a diagnosis of moderate chronic periodontitis. (C) Chest CT scan after 12 days of therapy showing significant reduction of the abscess lesion in the right upper lobe (arrow). (D) Chest CT scan after 54 days of therapy demonstrating near-complete resolution of the lung abscess (arrow). CT – computed tomography.