Radiological Evaluation of Artificial Stone Silicosis Outbreak: Emphasizing Findings in Lung Transplant Recipients

The aim of this study was to describe the computed tomography (CT) findings and correlate pulmonary function tests (PFTs) of silicosis patients with emphasis on the findings in lung transplantation (LTX) recipients. We studied the chest CT scans from 82 marble workers exposed to artificial stone dust and who had a diagnosis of silicosis, of whom 13 patients underwent LTX. Silicosis-associated findings were graded and correlated to concomitant PFT. A statistically significant inverse relationship was found between chest CT scores and PFT including forced expired volume in the first second (r = -0.54, P < 0.0001), total lung capacity (r = -0.4, P < 0.0001), and diffusion capacity for carbon monoxide single breath % (r = -0.6, P < 0.0001) parameters. Progressive massive fibrosis indicating advanced and complicated silicosis was found in 85% of LTX patients, as compared with 40% in patients with maintained pulmonary function. Ground-glass opacities were seen in some LTX patients with or without signs of progressive massive fibrosis. Two of these patients had silicoproteinosis diagnosed within the resected lung, indicating an acute or accelerated form of silicosis. This silicosis current outbreak is important because of the worldwide use of this and similar high-silica-content, artificial stone products, which can cause progressive severe forms of silicosis. Along with standard clinical assessment and PFT, CT parameters are indicative measures of the disease severity.