Sarcoidosis in a patient clinically diagnosed with silicosis; is silica associated sarcoidosis a new phenotype?

Abstract

A diagnosis of silicosis is made on the basis of exposure and typical radiological findings, according to the ILO's International Classification of Radiographs of Pneumoconiosis. Radiological patterns of silicosis can, however, resemble sarcoidosis. Sarcoidosis is a multi-systemic disorder of unknown etiology, although a role for initiating inorganic triggers such as metals or silica has been suggested. In this case report, we illustrate a patient previously diagnosed with silicosis based on exposure and radiological features, progressive under immunosuppressive treatment. In view of these findings, an open lung biopsy was performed and revealed sarcoidosis. The patient was effectively treated with infliximab. Further analysis showed the presence of silica in the granulomas. Sensitization to silica was also demonstrated, suggesting an association between silica exposure and sarcoidosis in this patient.

Sarcoidosis

“…Among the inorganic dust particles most consistently associated with increased risk for sarcoidosis are respirable crystalline silica (RCS) and silicates. 10,[15][16][17][18][19][20][21][22] Case Reports: Kawano-Dourado et al 15 27 In the 12-month period following exposure, the incidence rate was 86 per 100,000; and in 2015, the average annual incidence rate was 25 per 100,000. 27,28 During the period 1985 to 1998, Prezant et al 29 observed an average annual incidence rate among NYC firefighters of 12.9 per 100,000, with a range of 0 to 43.6 per 100,000.…”

Lymphadenopathy and Granulomas: Benignancy of Malignancy and Differential Diagnosis with Endobronchial Ultrasound-Transbronchial Needle Biopsy 19G Needle Fine-Needle Aspiration Biopsy

“…In the case of suspected TB, PCR is a rapid solution for the sputum sample where with a positive result we can immediately start therapy. In the case of TB we can have endobronchial lesions which have granulomas and the pathology report alone cannot distinguish sarcoidosis versus TB versus silicosis [ 8 , 19 ]. Other laboratory findings such as ACE or the bronchoalveolar lavage can assist us in the diagnostic workup of sarcoidosis; however, they assist as surrogate markers [ 20 ].…”

Sarcoid-like Granulomatous Lung Disease with Subacute Progression in Silicosis

“…Silica exposure has been associated with sarcoidosis or sarcoid-like granulomatous lung disease (8)(9)(10)(11)(12)(13). Epidemiological studies have noted a high incidence of sarcoidosis in patients with silica exposure (10,11).…”

“…Inhalation of beryllium can cause granulomatous lung disease that mimics sarcoidosis (7), and other metals and inorganic dust have also been associated with a granulomatous response (4)(5)(6). Silica might be a trigger for sarcoidlike granulomatous lung disease, and several studies have reported the association between silica exposure and sarcoidosis or sarcoid-like granulomatous lung diseases (8)(9)(10)(11)(12)(13).…”