Sarcoid-like Granulomatous Lung Disease with Subacute Progression in Silicosis

A 67-year-old man was admitted to our hospital with cough and fatigue. He had had long-term exposure to silica due to cement processing. Chest computed tomography showed bilateral centrilobular nodules, and hilar and mediastinal lymphadenopathy with calcification, suggesting chronic silicosis. Within a few months, these nodules enlarged, and bilateral patchy consolidations appeared. A lung biopsy revealed sarcoid-like granulomas with birefringent particles under polarized light without malignancy or infection. He was diagnosed with silicosis-associated sarcoid-like granulomatous lung disease, rather than sarcoidosis, according to the clinicopathological findings. His pulmonary manifestations improved after the discontinuation of silica exposure and combination therapy of corticosteroid and azathioprine.