RESUMO
Intercostal lung hernias are uncommon and usually a consequence of trauma or surgery. True spontaneous lung hernias are extremely rare, with only 51 cases identified over the past four-and-half decades. We report a case of nontraumatic chest wall ecchymosis secondary to spontaneous posterior-lateral lung herniation followed by a review of the literature. Interesting radiographic images are presented. The pathophysiology and therapeutic options of this condition are discussed. The case highlights that advanced chronic obstructive pulmonary disease (COPD) may be an etiological factor for the development of this rare entity, with cough being the precipitating event. Given the increasing prevalence of COPD, the authors believe further awareness of this pathology is needed.
RESUMO
BACKGROUND: COPD has traditionally been defined by the presence of irreversible airflow limitation on spirometry using either the GOLD (Global Initiative for Chronic Obstructive Lung Disease) or American Thoracic Society/European Respiratory Society criteria (lower limit of normal [LLN]). We have observed that some patients with clinical COPD and emphysema on chest CT scan have no obstruction on spirometry. The purpose of this study was to assess the prevalence of obstruction by GOLD and LLN criteria in patients with emphysema on CT scan and determine which radiographic criteria were associated with a clinical diagnosis of COPD. METHODS: We retrospectively analyzed the clinical records and spirometry of all patients who had radiographically defined emphysema on chest CT scans completed at the University of Vermont in 2011. We compared spirometric criteria and CT scan factors with the presence of clinical COPD based on chart review. RESULTS: We identified 274 patients with CT scan-defined emphysema. GOLD criteria detected obstruction in 228 patients (83%), and LLN detected obstruction in 206 patients (75%). However, GOLD failed to correctly identify 19 patients (6.9%) and LLN failed to identify 38 patients (13.9%) (average 10.4%) who had radiographic emphysema and a clinical diagnosis of COPD. Obese patients had a lower prevalence of obstruction whether classified by LLN or GOLD. Among patients with spirometric obstruction, there were greater degrees of emphysema and more severely increased airway wall thickness. Factors that were independently associated with clinical COPD were lower FVC % predicted, lower FEV1/FVC ratio, and increasing airway wall thickness. CONCLUSIONS: Spirometry missed 10.4% of patients with clinical COPD who have significant emphysema on chest CT scan.
