Multiorgan accelerated silicosis misdiagnosed as sarcoidosis in two workers exposed to quartz conglomerate dust

Abstract

IntroductionClusters of silicosis cases have been reported in the fabrication of quartz conglomerate, a new high-silica-content artificial stone for kitchen and bathroom benchtops (countertops).AimWe describe two cases of accelerated-type silicosis with hepatic granulomas arising in workers exposed to artificial quartz conglomerates.MethodsA confident diagnosis of multiorgan silicosis was based on high level of respirable silica in the workplace, typical radiological alterations in chest high-resolution CT, histological findings in the lung and liver, and detection of silica crystals in both tissues by phase-contrast polarising light microscopy and scanning electron microscopy and energy dispersive spectroscopy.ResultsThe development of the disease <10 years after the first exposure is consistent with an accelerated-type of silicosis. Compared with other studies related to quartz conglomerate exposure, we determined that the levels of airborne crystalline silica during activity in the finishing area were between 0.260 and 0.744 mg/m3, that is, much higher than the threshold limit value according to American Conference of Governmental Industrial Hygienists (0.025 mg/m3). Moreover, liver granulomas were associated with accumulation of crystalline silica particles in the hepatic tissue.ConclusionsQuartz conglomerate fabrication is a potentially dangerous occupation. General practitioners and physicians should have awareness of this newly described occupational hazard. Accurate occupational history is critical in avoiding misdiagnosis, as silicosis caused by inhalation of dust from artificial quartz conglomerates may exhibit atypical presentation. These features seem to be related to the extremely high level of silica exposure and, possibly, to an increased toxicity of the dust generated in this process.

Accelerated silicosis with bone marrow, hepatic and splenic involvement in a patient with lung transplantation

“…Apart from the well-described lung deposition of particles by inhalation or in lymph nodes through lymphatic route,1 17 almost no references have been found about the dissemination of silica particles to other extra-pulmonary sites. Although swallowing could be the way of particle acquisition through the portal system and eventually hepatic deposit, this has not been proved yet 2 18 19…”

“…Indeed, the use of new quartz conglomerates in construction is the cause of increased silicosis incidence 2 3. However, workers may be exposed to crystalline silica in many other industries, such as underground and open pit mining, ceramics, gypsum wall installation, glass manufacturing, smelting, agriculture and car repair and, of course, work in quarries and work with sandblasting materials.…”

Sarcoidosis and silica dust exposure among men in Sweden: a case–control study

“…[11][12][13] However, another case report argues that some cases of sarcoidosis might be misclassifications of silicosis. 14 The aim of this study is to investigate whether sarcoidosis is associated with occupational exposure to respirable silica dust.…”

“… 11–13 However, another case report argues that some cases of sarcoidosis might be misclassifications of silicosis. 14 …”

EASL Clinical Practice Guideline: Occupational liver diseases

“…Unpredictable routes of exposure such as breakdown, cleaning and maintenance of machinery, and accidental leakage still occur though and new causes of OLD will potentially come to light, such as liver silicosis, particulate matter air pollution and increasing use of nanomaterials. [1][2][3] Moreover, the diagnosis of OLD remains challenging in clinical practice due to the lack of pathognomonic signs and sensitive biomarkers of liver injury. Whilst acknowledging that viral infections in hospital workers are recognised as OLDs, herein, attention will only be paid to chemically induced liver injuries.…”