Diffuse pulmonary ossification in a patient exposed to silica.

Despite drainage, because the pneumothorax was persistent, the patient underwent video-assisted thoracoscopic surgery 2 days later. The lung was particularly ‘‘rigid’’ and lamellar deposits of calcified osteoid material, with marrow elements in the alveolar spaces and interstitium, were found in the lung biopsies (fig. 3). The lung parenchyma was otherwise normal. There was no suggestion of any pneumoconiosis, fibrosis or inflammation, and no evidence of venous congestion or iron deposition. The final diagnosis was DPO.