Chronic interstitial pneumonia with honeycombing in coal workers.

Background: Coal worker's pneumoconiosis (CWP) results from coal mine dust inhalation.

Patients And Methods: We report here the presence of a chronic interstitial pneumonia (CIP) with honeycombing in 38 cases of coal miners, with or without CWP. The 38 patients were selected on the basis of clinical criteria which are unusual in CWP, i.e. fine inspiratory crackles and severe dyspnea. There were 37 men and one woman; mean age was 67.5 +/- 9.1 years. Thirty-two were smokers. Duration of exposure was 26.7 +/- 9.9 years. All the patients had clinical examination, chest radiography, computed tomography (CT), lung function, laboratory investigations, wedged fiberoptic bronchoscopy with bronchoalveolar lavage (BAL). In eight cases, lung specimens were obtained (lung biopsy n = 6, explanted lungs n = 2).

Results: Seventeen out of 38 had finger clubbing. 17 had radiological signs of CWP limited to the upper lobes (n = 11) or diffusely distributed (n = 6). CT showed honeycombing (36 cases), and/or ground glass opacities (30 cases) with traction bronchiectasis (8 cases) predominant in the lower lobes. BAL analysis demonstrated an increased percentage of neutrophils (9.4% +/- 6). Lung function showed a restrictive pattern (TLC = 75.1% +/- 16 and FVC = 79.7% +/- 17 of predicted values) associated with a decreased DLCO (50.4 % +/- 22.9 of predicted values) and hypoxemia (at rest = 65.9 mmHg +/- 13.5, upon effort = 56.5 mmHg +/- 13.4). Lung specimens demonstrated in 2 cases a homogenous interstitial fibrosis of intra-alveolar septum with an accumulation of immune and inflammatory cells without temporal variation and with obvious honeycombing. The 6 other cases showed features of usual interstitial pneumonia.

Conclusion: In presenting these cases, we would like to alert other clinicians to a possible association between CIP with honeycombing and coal dust exposure, with or without associated CWP.