Comparison between community-acquired pneumonia and post-obstructive pneumonia associated with endobronchial tumors

Endobronchial tumors can infiltrate the bronchial wall or protrude into the bronchial lumen, causing post-obstructive pneumonia (POP). Differentiating between POP and community-acquired pneumonia (CAP) is challenging due to similar clinical, laboratory, and imaging findings, which can delay the diagnosis and treatment of endobronchial tumors.

We compared general demographic information, laboratory test results, lung CT images, bronchoscopic observations, pathological findings between the POP group and the CAP group.

(1) The POP group consisted mainly of older individuals (mean age 69 vs. 56 years; P < 0.05), males (93.4% vs. 47.1%; P < 0.05), and smokers (67.2% vs. 14.7%; P < 0.05). Clinical symptoms varied, with chest pain (23.0% vs. 11.8%; P < 0.05) and hemoptysis (26.2% vs. 10.8%; P < 0.05) more prevalent in the POP group. MSCT showed that bronchial wall thickening, bronchial stenosis, occlusion, obstructive emphysema, mucoid impaction, and endobronchial shadows occurred more frequently in POP, while consolidation and exudation shadows were predominant in CAP (P < 0.05). (2) In the POP group, neoplasms were the most frequent bronchoscopic findings (57 cases, 93.44%), especially in the upper lungs. Squamous cell carcinoma was the primary pathological type (52 cases, 85.25%). The average delay in diagnosing endobronchial tumors was 214.8 days. In the POP group, 34 cases (55.74%) had abnormal CT images in the past and did not undergo bronchoscopy, resulting in delayed diagnosis. (3) Factors such as gender, age, bronchial occlusion, stenosis, mucus embolism, and intraluminal shadow were determined to be independent risk factors for endobronchial tumors (P < 0.05 and OR > 1).

Endobronchial tumors combined with POP are easily misdiagnosed as CAP in the early stage. Factors like bronchial occlusion, stenosis, mucus embolism, and intraluminal shadows on MSCT are significant independent risk factors for these tumors, indicating the need for early bronchoscopy.